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COPYRIGHT DEPOSIT. 



A LABORATORY GUIDE 

AND OUTLINES IN 

HISTOLOGY 



REVISED EDITION 



BY 

CHARLES H. DeWITT, M. S. 

ANATOMY AND HISTOLOGY CHICAGO COLLEGE OF MEDICINE AND 

SURGERY, HISTOLOGY AND BACTERIOLOGY IN CHICAGO 

COLLEGE OF DENTAL SURGERY, HISTOLOGY 

IN VALPARAISO UNIVERSITY 



Valparaiso, Indiana 

Charles H. DeWitt 

1908 



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COPYRIGHT I908 

BY CHARLES H. DeWITT 
Valparaiso, Ind. 



PREFACE 



The author has felt the need of a laboratory guide in this subject which 
would meet his own particular requirements and that is the only excuse offered 
for this work 

It has been the aim of the author to give the student such help as experience 
has shown that he needs, and to direct his study by question rather than by 
direct statement. 

This book has been designed to supplement the text and it presupposes 
that the student has had lectures upon the topics, as well as his own text-book 
study, and it should be used in no other way. 

Experience has shown that while the text-books have excellent illustrations 
the student does not use them as he should in his microscopic study of the 
tissues. With this in view this work has been illustrated by sketches and 
photo-micrographs. These have been made by the author from his own pre- 
parations or those of his students, unless otherwise credited. The aim has 
not been to represent details of structure so much as it has been to show the 
structures as the student finds them in his own specimens. The camera lucida 
was used for most of the work, and the structures have been carefully labeled 
to aid the student in their identification and study. 

It will perhaps be said that the student has received too much help and that 
his drawings will be made from those in his laboratory guide rather than from 
the section under his microscope. While this may be true to some extent, yet 
the fact that he has a definite plan for the study of each section, and that he 
knows just how to proceed, outweighs this objection in the opinion of the 
author who has never known a beginner in the study of Histology to say that 
he has had too much light thrown upon the subject. 

To a certain extent histological technique has been combined with labora- 
tory directions for study since the student proceeds more intelligently in this 
way. While it may seem unnecessary to repeat the directions for staining and 
mounting each section, yet students are found in every class to whom such 
advice is always helpful. 

Drawings and sketches should be made even though the average medical 
student considers it a waste of time, for only in this way will the different 
structures and structural relations be fixed in mind. Sketching and drawing 
are very necessary adjuncts to thorough anatomical study either macroscopic 
or microscopic. 

Only those methods in common use by students are described, detailed ex- 
planations and special technique being omitted since there are plenty of splendid 
works devoted to these things. The whole aim has been to give the student a 
simple and practical working guide. Corrections and suggestions from teachers 
of Histology will be greatly appreciated. 

The author is indebted to his fellow-teachers in Valparaiso College for 
many helpful suggestions and criticisms which have aided very greatly iti the 
preparation of this work. CHARLES H. DEWITT, 

Valparaiso, Indiana, November i, 1904. 



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General Suggestions to the Student. 

After the student has been assigned a place at the table 
and a locker, he will be held strictly to account for the proper 
care of the same. Much of the best work done in this subject 
is done in the laboratory, and hence we expect very careful at- 
tention to every detail of this work. 

Each student will be assigned a microscope, and he will be 
fully instructed in the use and care of it, and will be expected 
to use it carefully, and care for it properly, during the time it is 
assigned to him. Any injury to the microscope due to careless- 
ness on the part of the student must be made good by the one 
responsible for such injury. If the microscope does not work 
properly, or if it needs any attention, report it to the instructor 
at once. 

Reagents must not be allowed to come in contact with any 
part of the microscope. The slides should be carefully cleaned 
and dried before placing them upon the stage of the microscope. 
Should accidents happen, kindly report them at once, as the 
proper attention at the time will often prevent serious injury 
being done. 

Filter paper, blotters, and waste material should be placed 
in the jars provided for that purpose. Such material must not 
be thrown upon the floor, table, or in the locker. 

Each student will be expected to provide himself with an 
outfit similar to the following: 

One box, arranged for such work, to hold student's material ; 

One box for ioo slides; 

One pair coverglass forceps ; 

One section lifter ; 

Two needles mounted in wooden handles for teasing tissues ; 

Two camel's hair brushes for handling sections ; 

Six medicine droppers or short pipettes ; 

One-half gross medium thin slides ; 

One ounce coverglasses, i8mm. circles No. 2; 

150 slide labels; 

One package 3 inch filter paper; 

Six 3 dram vials with corks ; 

Canada balsam in collapsible tube container. 



6 A LABORATORY GUIDE IN HISTOLOGY. 

The stains, oils, and alcohols, commonly used by the student, 
will be furnished to him in proper receptacles. These stains 
and reagents should be carefully protected from dust and evap- 
oration when not in use. The stains should be filtered frequently 
so that no precipitates will appear in the stained tissues. Special 
stains and reagents will be secured from the instructor when 
needed, and they should be returned to him at the close of the 
laboratory period. 

The drawings and sketches suggested by the laboratory 
manual must be made from the specimens while in the labora- 
tory. Some of the labeling and lettering may be done later, but 
at least the complete outlines of all sketches and drawings must 
be made directly from the object. These drawings should be 
made with a hard pencil without much shading. Make the out- 
line lightly at first so that corrections may be made if necessary. 
In the drawings for this work every line should represent a 
definite part of the structure. Do not put in any lines, or marks, 
unless they thus represent something. In some cases a judicious 
use of colors may be helpful in representing the general structure, 
but colors should never be used for representing the minute 
details of the histology of any tissue or organ. 

All drawings and their parts must be neatly and completely 
labeled. The labeling in this book will indicate the manner of 
designating the parts of a drawing. You may use letters if you 
prefer. The magnification should be indicated wherever it is 
possible to do so. 

The student is expected to work independently, and to follow 
closely the suggestions given in this guide. He is encouraged 
to ask questions bearing upon his work at all times, and in his 
study of a given specimen he should attempt to answer and to 
follow all the questions asked, since these questions are designed 
to guide him in the proper order of study, and also to impress 
upon his mind those things which are most important. 

The student will find formulae for stains and reagents at 
the close of this work. He is earnestly desired to familiarize 
himself with them as they are used, so that his work may be 
performed with a greater degree of intelligence. 

The outlines beginning on page 116 are designed to aid the 
student in his study of this subject. In these outlines he has 



A LABORATORY GUIDE IN HISTOLOGY. 7 

given the things which are most important, the things he needs 
to understand and to remember. The writer believes in the 
topical or outline method of teaching and study, and he believes 
that the student who follows a definite plan of study accomplishes 
most with least effort. These outlines are also very valuable 
as a means of reviewing the subjects at a later time. In the 
outlines given of the nervous system gross anatomy and histology 
are not sharply separated. Indeed, these must be combined in 
the study of either the histology or anatomy of the nervous sys- 
tem if the teacher is to secure the best results. 

General Explanation of the Process of Tissue Preparation. 

(1) Killing and Fixing. The fresh tissue must be treated 
with a killing and fixing agent in order that the cells may be 
killed before undergoing post-mortem changes. They must now 
be fixed in that condition and the cell contents rendered insoluble 
to the reagents used in the further treatment of the tissue. The 
pieces of tissue should hot be large, so that the killing and fixing 
may be the more readily accomplished. The volume of the re- 
agent should be from fifteen to fifty times that of the material. 

(2) Washing. With the exception of the alcohols and 
formalin, most killing and fixing agents must be washed out as 
completely as possible before proceeding further, for the reason 
that some fixing agents will hinder the action of the stains, if 
present in the tissue in excess, and in other cases precipitates will 
be formed which must be removed. This is especially true of 
those fixing agents that contain salts of chromium. The washing 
is usually done in running water, but after certain killing and 
fixing fluids, alcohol must be used. If running water is not 
accessible a large volume of water should be used and it must 
be changed frequently. The best results are obtained by cover- 
ing the vessel containing the tissues with mosquito netting, to 
prevent the loss of the tissue, and placing it under the tap so 
that the water may drip into the vessel constantly for the re- 
quired length of time, usually twenty-four hours. 

(3) Hardening with Alcohol. After washing in water the 
tissue will require further hardening and dehydration for which 
alcohol is usually used. This must be a gradual process, there- 



8 A LABORATORY GUIDE IN HISTOLOGY. 

fore, after washing in water place the tissue in 35% alcohol for 
several hours. Then use 50-60% alcohol for five or six hours, and 
store the tissue in 80% alcohol if not wanted for immediate use. 
If it is desired to imbed the tissue at once transfer the tissue 
from the 80% alcohol to 95% where it is left for several hours, 
depending upon the size of the pieces and the character of the 
tissue. Transfer to absolute alcohol to complete the dehydra- 
tion. This process is very important since a very slight amount 
of water in the tissue will ruin it, or at least impair its value for 
histological study. 

(4) Clearing. Up to this point the process is the same 
whether the tissue is to be imbedded in celloidin or paraffin. 
Xylol or chloroform are the clearing agents commonly used prior 
to imbedding in paraffin and ether for imbedding in celloidin. 
The use of a clearing agent at this point is to remove the alcohol, 
since alcohol is not a solvent for the imbedding media to be used 
later, hence the removal of the alcohol is absolutely essential. 
The transfer from the absolute alcohol to the clearing oil should 
be made gradually by first using equal parts of alcohol and the 
clearing agent for a short time and then use the pure ether, chlo- 
roform, or xylol for the proper time as indicated below. 

(5) Imbedding. For some purposes it is merely necessary 
to surround the tissue with the imbedding substance, but for 
most work the tissues must be penetrated by and completely 
saturated with the imbedding medium. This latter is known as 
interstitial imbedding. The choice of imbedding material de- 
pends upon the use to which the tissue is to be put, and the 
thickness of the sections desired. The transfer from the clearing 
oil to the medium used for imbedding should be a gradual process. 
A general or suggestive outline for imbedding in celloidin and 
paraffin will be found below. 

(a) Celloidin Imbedding. 

1. Transfer from absolute alcohol to equal parts of 
ether and absolute alcohol for 6 to 12 hours. Why? 

2. Transfer to pure ether for 6 to 12 hours. Why? 

3. Place the tissue in thin celloidin for 24 to 48 hours 
or longer. 



A LABORATORY GUIDE IN HISTOLOGY. 9 

4. Place the tissue in thick celloidin for 12 to 48 hours 
or longer. 

5. Fasten to Blocks. Select from the jar of alcohol in 
which they are kept a fiber block having an end surface 
slightly larger than the piece of tissue to be blocked. Dip 
the end of the block into ether-alcohol, and, after a moment, 
into the thick celloidin. Remove the piece of tissue from the 
thick celloidin, place in the desired position upon the end of 
the block, and press it down somewhat firmly against the 
block. Let it dry a moment and dip it into the thick celloidin 
or pour a little of the celloidin over the surface so as to form 
a coat of celloidin around the tissue. After drying a moment 
in the air, place the block in chloroform for a few minutes to 
harden the celloidin, and then complete the hardening by 
placing the block in 70 or 80% alcohol. The tissue thus im- 
bedded may be kept indefinitely in 70% alcohol. If the block 
be soaked in chloroform for an hour before cutting thinner 
sections can be obtained. Instead of imbedding on blocks 
as above, the pieces of tissue may be properly oriented in the 
bottom of a Petri dish and covered with thick celloidin. Al- 
low it to harden in the air until a thin film forms. Now flood 
the surface with chloroform and cover for thirty minutes. 
Pour off the chloroform into the "used chloroform" bottle, and 
cover the surface with 80% alcohol. After twenty-four 
hours, cut the celloidin around the tissues so as to leave a 
margin of about a centimeter around each piece. Store 
pieces in the 80% alcohol until ready to cut sections. These 
celloidin blocks may be clamped into the holder of the micro- 
tome ready for section cutting. They are best fastened to 
fiber blocks, however, before cutting sections. To do this 
dip the lower end of the celloidin block into ether-alcohol 
for a few minutes to soften the celloidin. Place a drop of 
thick celloidin on a fiber block and press the celloidin block 
down into it. Harden in chloroform for ten minutes and cut 
sections, or store in alcohol until needed. For general pur- 
poses, and" especially for student use, celloidin is to be pre- 
ferred for imbedding because the sections are more easilv 
handled than paraffin sections. The objection made to the 
use of celloidin, by some workers, that sections cannot be cut 



io A LABORATORY GUIDE IN HISTOLOGY. 

thin enough is not a valid one, for if the tissue be properly 
prepared for sectioning., the sections may be cut as thin as 
necessary for ordinary purposes. We cut celloidin from 4./* 
to 15/x, average 8 or lop, which does very nicely. The diffi- 
culty that some workers have with celloidin can usually be 
traced to some defect in technique. We use celloidin but once 
for infiltrating tissues for when it contains fat, abstracted by 
the ether used as a solvent for the celloidin, it will not harden 
properly. 

6. Cutting Sections. The sections should be cut with a 
sliding microtome. The knife should set as obliquely as 
possible. The tissue and knife should be flooded with 80% 
alcohol while cutting, and as soon as cut the sections should 
be transferred with a camel's-hair brush from the knife to 
80% alcohol where they remain until desired for staining. 

Staining and Mounting Celloidin Sections. 

Hematoxylin and Eosin Method. 

1. Transfer the section from the 80^ alcohol in which 
they have been preserved to water in a water glass and allow 
it to remain a minute or two. Remove the section from the 
water with a camel's-hair brush by dipping the brush be- 
neath it and then unrolling the section on a clean slide. If 
you have any difficulty in unrolling the section from the 
brush, you may dip the slide beneath the section and draw it 
onto the slide with the brush. Drain the excess of water 
from the section by holding the slide edgewise on a piece of 
blotter or filter paper. With medicine dropper, or pipette, 
cover the section with hematoxylin and stain for from one to 
five minutes, the exact time being determined by trial. 

2. Wash in tap-water for tAvo minutes. To do this dip 
slide and section into the water glass and gently move the 
slide back and forth. W nen washed remove the section from 
the water and place it on the slide as above. If the section is 
over-stained, it may be de-stained by using acid-alcohol for 
a few seconds. Follow the acid-alcohol with alkaline-alcohol 
until the tissue turns from a red to a blue color. Wash in 



12 A LABORATORY GUIDE IN HISTOLOGY. 

there is an air space left beneath the cover, add a drop of 
balsam at the edge so that it may flow under by capillary at- 
traction and fill the space, but do not lift the cover. In case 
the section has a milky appearance after applying the balsam, 
and if no change was noted when the clearing oil was ap- 
plied, you may know that all of the alcohol was not replaced 
by the oil, in other words it has not been cleared sufficiently. 
In such a case, treat the section for a second time with the 
oil. Dehydration and clearing must be complete if good spec- 
imens are to be secured. 

7. Label. The label should be neatly printed or writ- 
ten, and on it should appear the name of the specimen, the 
number of the section, and your name or initials. The ends 
of the slide should be wiped free from oil before applying the 
label. The label should be attached to the left end of the 
slide. After finishing the preparation it should lie face up 
for twenty-four hours, otherwise the balsam is likely to run 
and the coverglass to slip from the specimen. Any excess of 
the balsam around the margin of the coverglass may be 
scraped away when dry, and the cleaning may be completed 
by using a cloth wet with xylol. 

8. General Remarks. The outline for staining and 
mounting given above is meant to be suggestive merely and 
it must be varied somewhat with different tissues. The stu- 
dent will soon learn by experience and careful observation 
when a tissue is properly stained. This experience only comes 
with patient and careful attention to the details of the stain- 
ing technique. 

(b) Paraffin Imbedding. 

1. Transfer from absolute alcohol to equal parts of ab- 
solute alcohol and chloroform, 6 to 12 hours. 

2. Pure chloroform, 6 to 12 hours. 

3. Chloroform saturated with paraffin (cold), 5 to 6 
hours. 

4. Chloroform saturated with paraffin (in paraffin 
oven), 1 to 2 hours. 

5. Soft paraffin, 45°, in oven, 1 to 3 hours. 



A LABORATORY GUIDE IN HISTOLOGY. 13 

6. Hard paraffin, 5o°-54°, 1 to 2 hours. 

7. Imbed in paper boxes. Using paper of firm texture 
make small boxes by moulding the paper about wooden 
blocks of suitable size. The instructor will show you how 
this is done. Number the box to correspond with the number 
in your tissue list. Place the tissue in' the box with the sur- 
face from which it is desired to cut sections resting on the 
bottom and cover with melted paraffin. Cool quickly by 
holding the box in ice-water, or in cold running water. After 
the paraffin is cold remove the paper and mark the paraffin 
block with a number to correspond with that of your tissue- 
record. Instead of paper boxes metal L's especially prepared 
for such work may be used. These should be placed on a 
glass plate which has been rubbed with a cloth saturated 
with glycerin to facilitate the removal of the L's. After pour- 
ing melted paraffin over the tissues, allow it to cool until a 
film forms on the surface of the paraffin and plunge into cold 
water. 

8. Cut sections. 

9. Fasten the section to a clean slide with Mayer's fixa- 
tive. Apply the fixative evenly and thinly with the clean 
finger tip. 

10. Heat carefully to the melting point of paraffin and 
place it in turpentine to dissolve the paraffin, after which 
treat it with xylol, 1 to 2 minutes. 

11. Treat the slide with absolute alcohol, 1 to 3 minutes; 
95% alcohol, 1-2 minutes; 80% alcohol, 1 minute; 50% al- 
cohol, 1 minute ; water, 1 to 3 minutes. 

12. Stain in hematoxylin, 1 to 5 minutes. If overstained 
treat as for celloidin sections. The staining is more precise if 
overstained and then differentiated with acid-alcohol or am- 
monia alum. Wash thoroughly after either acid-alcohol or 
ammonia alum. 

13. Stain in eosin, and dehydrate as for celloidin sections. 

14. Clear with oil of cloves, or Eycleshvmer's mixture. 5 
to 15 minutes, mount in balsam, and label. 

The student should consult his text-book in Histology for a 
more detailed account of the processes of tissue preparation than 
can be given in this laboratory guide. 



14 



A LABORATORY GUIDE IN HISTOLOGY. 



Cells. 



Plant Cells. With forceps remove a small piece of the epi- 
dermis from a leaf of live-forever. Place it on a slide, add a drop 

of water, and cov- 




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er with a cover- 
glass. Study with 
low power. Ob- 
serve the follow- 
ing: 

The large epi- 
dermal cells with 
their irregular out- 
lines. Search for 
the nucleus, spher- 
ical in form, and 
more refractive than the cytoplasm. The cytoplasm is granular 
and grayish in color. Look for vacuoles. Sketch a few cells 
carefully. See Fig. i. Using the high power, try to find cells in 
which there is a circulation of the protoplasm made evident by 
movements of the granules. Note the direction of the currents. 
Do you find the molecular or Brownian movement? Make a 
sketch and show by arrows the direction of the currents in the 
cytoplasm. 



x \ oA. . X-» ov,o t* ya\* w\\>t \ox -*a>*,\ \*, t qX«k a.oo. 



Study of Mitosis or Karyokinesis. The root tips of the onion 
or of Podophyllum were fixed in a chrom-acetic mixture, hard- 
ened in alcohol, and imbedded in paraffin. Longitudinal sections 
were made and. fastened to the slides with Mayer's albumin 
fixative. Take the slide given you, warm gently to soften the 
paraffin and place it in turpentine or xylol for several minutes 
until the paraffin is removed. Take through the grades of alcohol 
(absolute, 95%, 80%, etc., two or three minutes in each) to water 
and stain deeply with Delafield's hematoxylin. Remove the ex- 
cess of stain with acid alcohol, wash thoroughly in tap-water, 
stain lightly with eosin, dehydrate, clear in oil of cloves, and 
mount in balsam. Study under high power and trace as many of 



A LABORATORY GUIDE IN HISTOLOGY. iq 




Fig. 2. Mitosis in Podophyllum peltatum x800. 




Fig. 2(a). Mitosis in egg of Ascaris showing the 
centrosome, attraction spheres, and the chromo- 
somes in the diaster. 



i6 



A LABORATORY GUIDE IN HISTOLOGY. 



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the stages of mitosis as possible. Make sketches of cells showing 
the various forms of mitotic figures. See Fig. 2 and Fig. 2(a). 

Animal Cell Movements. Study under high power amoebae 
obtained by allowing a bit of fish, a fresh water mussel, or ma- 
terial collected from a pond, to decay in water. As soon as a 

slight film forms on the 
surface a drop should be 
placed on a slide covered 
and carefully examined. 
Search for small and 
nearly colorless bodies 
which are slowly chang- 
ing their form. How 
does the animal move? 
Can you distinguish a 
clearer outer zone, the 
ectoplasm, from the 
more granular endo- 
plasm? Can you find a 
nucleus? A contractile vacuole? If so, study carefully and de- 
termine its function if possible. Do you find a cell wall? Make 
a series of at least five sketches to show the changes in form 
which the cell undergoes. See Fig. 3. 

Animal Cells. Pieces of the ovary of a very young dog were 
fixed in bichloride of mercury, or Flemming's fluid, hardened- in 
alcohol, and imbedded in paraffin. Prepare your slide by care- 
fully cleaning with alcohol and spread a very thin layer of Mayer's 
albumin fixative upon it. Avoid using too much fixative. It is 
well to add as little as possible and spread it with the clean 
finger tip and remove in this way as much as possible. Transfer 
the section from the warm water bath to the slide by placing 

y the slide under the section 




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and lifting it from the water, 
and carefully blot. (Cigar- 
ette paper makes splendid 
blotters for this purpose). 
Warm carefully over a gas 
flame or alcohol lamp until 



A LABORATORY GUIDE IN HISTOLOGY. 



17 



the paraffin begins to melt and remove the paraffin with turpen- 
tine and xylol. Since dishes of xylol soon become charged with 
paraffin, as some one has suggested, it is a good plan to flood 
the slide with turpentine and drain on a blotter and then add 
xylol and follow with absolute alcohol, 95%, 80%, 50%, and water, 
if stain used be an aqueous solution, otherwise use alcohol for 
the last time, of the same grade as that used in the stain. Stain 
with Delafield's hematoxylin and remove the excess of stain with 
acid alcohol, or with a 3% aqueous solution of ammonia alum, 
and wash in water. Stain lightly in eosin, dehydrate, clear in 
oil of cloves for five or ten minutes, and mount in balsam. Study 
under low power, noting form of cell, relatively large nuclei, 
nucleoli, etc. Study under high power and make sketches show- 
ing the general structure of a typical large animal cell. See Fig. 4. 



KVNttAlsk* - - - 



Epithelial Tissues. 

Squamous Epithelial Cells Unstained. Scrape the inside of 
the lip or cheek with a clean scalpel and mount the scrapings in 

a drop of physio- /^V.C^^^Wv.A.v. 

logical normal 
salt solution, or 
in the saliva, and 
study under high 
power. Note the 
shape and size of 
the cells and the 
shape and posi- 
tions of the nuc- 
lei. Do any cells *\ t c * <s CC\\\. 
have two nuclei? 3 « a \ wv^. 
Is the protoplasm clear or granular? Do you find any "salivary 
corpuscles" or leucocytes? Make sketches of several cells and 
label the parts. See Fig. 5. 

Stained Squamous Cells. Make a cover-glass preparation In- 
spreading material obtained as above between two clean cover- 
glasses, separate them by a rotary movement and dry in the air. 
Place in cover-glass forceps and fix by heat, passing quickly three 




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i8 



A LABORATORY GUIDE IN HISTOLOGY. 



times through the flame of a Bunsen burner, or an alcohol lamp, 
and stain with hematoxylin and eosin. Dry carefully and mount 
in balsam. Study as above and sketch several cells. 

Squamous Epithelium of a Frog. A frog was kept in a glass 
jar for several days until portions of the epidermis were shed. 
The pieces were washed in water and fixed in alcohol, after which 
they were stained in hematoxylin and eosin, dehydrated in alco- 
hol, cleared with oil of cloves, or Eycleshymer's mixture. Take 



v^.t.o\\WV 




them from the oil, place on a slide, and mount in balsam. Study 
the surface view of squamous epithelium thus prepared. Note 
the shape and size of the cells with their granular protoplasm 
and the intercellular cement. Do you find any intercellular 
spaces? Sketch a portion of the field showing form of the cells, 
nuclei, and their relations to each other. See Fig. 6. 




Stratified Squamous Epithelium. You will receive a section 
of the oesophagus of a cat which was imbedded in celloidin. Stain 



A LABORATORY GUIDE IN HISTOLOGY. 19 

in Delafield's hematoxylin, excess of which may be removed 
with ammonia alum (3%), or with acid alcohol, wash in tap- 
water, and stain lightly with eosin. Dehydrate, clear in phenol- 
xylol, and mount in balsam. 

Study the epithelial lining, first under low power and then 
under high power. Note the layers of cells, columnar in the 
lower stratum and gradually becoming flattened as they approach 
the surface. Do the nuclei change in shape and structure? Do 
you note any change in the protoplasm of the cells of the different 
layers? Make a sketch under high power to show the character 
and arrangement of the cells. See Fig. 7. 

Stratified Transitional Epithelium. Pieces of bladder were 
fixed in alcohol, imbedded in celloidin, and sectioned. Transfer 
the sections to water and stain in Delafield's hematoxylin and 
eosin. Dehy- 
drate, clear in 
Eycleshymer's 
mixture, or phe- 
nol-xylol, and 
mount in bal- 
sam. Study the 
epithelium un- 
der low and ^_ s . 
high power. \ \flc.V XxOo^^oyv^x^q/^X^^^ 
How many * 

strata of cells do you find? Does the number vary in different 
parts of the section? What is the form of the cell bodies of the 
deeper strata? Why do the cells vary in form? Do the super- 
ficial cells have more than one nucleus? Sketch a portion of the 
epithelium. See Fig. 8. 

Fresh Ciliated Epithelium. Carefully scrape the palate of a 
frog with a dull scalpel and mount the scrapings on a slide in 
normal salt solution. Study under high power noting the gen- 
eral form of the cell, the nucleus, and the movement of the cilia. 
How do the cilia appear to move? Sketch a few cells. 

Stained Ciliated Epithelium. Make a cover-glass smear of 
material secured as above, dry in the air and fix by passing rap- 




20 A LABORATORY GUIDE IN HISTOLOGY. 

idly through a flame two or three times, or expose to the vapor 
of formalin in a covered water-glass for ten minutes. Stain in 
hematoxylin and eosin, wash, dry, and mount in balsam. Study 
under high power and sketch a typical cell. 

Isolated Columnar Epithelial Cells. Macerate the mucous 
membrane of the small intestine of a cat in 33% alcohol for thirty- 
six hours. Tease a portion in dilute glycerin and cover. Tease 
another portion on a cover-glass, dry and fix by passing over a 
flame, stain in hematoxylin and eosin, wash in water, dry thor- 
oughly, and mount in balsam. Study under high power. Is the 
protoplasm clear or granular? Do the cells show striations? Do 
they possess a cuticular border? Note the shape and position of 
the nucleus. Sketch a few cells and label the parts. 



Wo?* 

w 



V\c^*\&t&*t &A*&- 






Columnar Epithelial Cells in Sections. The intestine of 
Necturus was hardened in alcohol, imbedded in celloidin, and 
sectioned. Stain in hematoxylin and eosin, dehydrate, clear in 
Eycleshymer's mixture, and mount in balsam. Study and sketch 
a few cells under high power. The cells of Necturus are very 
large, easily recognized, and easily studied. See Fig. 8(a). 




A LABORATORY GUIDE IN HISTOLOGY. 21 



Mesothelium and Endothelium. 

Mesothelium. Carefully remove the mesentery from the in- 
testine of a cat, rinse thoroughly in distilled water to remove any 
foreign substances that may be present, and place in the dark in 
a 1% solution of silver 
nitrate from ten to fif- 
teen minutes, or until 
it becomes somewhat 
opaque. Rinse in dis- $\\<\*i\qXov~ ' 
tilled water and expose 
to the light in water or ' \\ . \\ 
m 10% formalin until 
the silver is reduced C* * Yv\ » «. JlV \\ 1 

giving a brown color. tJ \ 

Rinse in water, stain in hematoxylin, dehydrate, clear, and 
mount in balsam. It is probably best to pin out the mesentery 
on thin sheets of cork until after the dehydration and clearing 
as it prevents the rolling and shriveling of the material. Study 
under high power, noting the shape and relation of the cells. Do 
you find intercellular spaces? Do you find stomata or pseudos- 
tomata? Sketch a few cells carefully. See Fig. 9. 

Endothelium. The endothelial cells of the mesenteric capil- 
laries are best shown by injecting the vessels of a small animal 
through the thoracic aorta. Chloroform a cat and when com- 



pletely anaesthetized, open the thorax and incise the heart so as 
to remove as much of the blood as possible. Inject from 7$ to 
100 c. c. of a 1% solution of silver nitrate, and after fifteen or 
twenty minutes inject from 100 to 150 c. c. of a 10% solution of 
formalin. After a few minutes open the abdominal cavity and 




22 



A LABORATORY GUIDE IN HISTOLOGY. 



expose the mesentery to the light. When the reduction of silver 
has occurred, remove pieces of the mesentery, wash in water, 
stain in hematoxylin, dehydrate, clear, study, and sketch under 
high power. See Fig. 10. 



Fibrous Connective Tissue. 

Unstained White Fibrous Tissue. Place a drop of physio- 
logical normal salt solution on a glass slide, and in this tease 
carefully with needles the portion of tendon given you by the 
instructor. Add another drop of salt solution if necessary, and 
cover with a coverglass. Study under the low power and then under 

the high power. 

How are the 

M fibrillse ar- 

i"^- ranged? Do 

they branch or 
'anastomose? 
Sketch. See 
Fig. ii. Add a 
* little dilute 

taxvA&b. acetic acid 

\Ma ^ (i%) at one 

^\% edge of the cov- 

a er-glass, hold a 

. piece of filter 

YvoA\.V^vv»\U V^Wv^ / \\vbv^ t\ \u\b0Vv.Sv Wrt. paper at the op- 
O * posite side and 

thus replace the salt solution by the acetic acid. Remove any 
fluid remaining around the cover-glass with the filter paper and 
examine. What is the effect of the acid? Boil a piece of the 
tendon for some time. What is formed? What are the charac- 
teristics of white fibrous tissue? 

Stained White Fibrous Tissue. A piece of tendon was hard- 
ened in alcohol, stained in borax-carmine, dehydrated, imbedded 
in celloidin, and sectioned longitudinally. The section given you 
is in clearing oil and should be mounted in balsam. Are cells 
present? How are the fibers arranged? Study and sketch under 
high power. 





A LABORATORY GUIDE IN HISTOLOGY. 23 

Fresh Yellow Elastic Tissue. Tease a portion of the liga- 
mentum nuchse of the ox in salt solution, cover and examine. 
Describe the general appearance of the fibers. Do they branch 
or anastomose? 
What position 
do the free ends 
assume? Are 
the fibers ce- 
miented into 
bundles? Are 

white fibers ^, ~'»vn 

present? Add ^*"W*5ta v^%U\\Wk,. * v * o^ N 

acetic acid as * 

above. What isY\ou\%XAfc4^ \xW*V><o>^ 
the result? * d ^ 

Boil as above. What is formed as a result of the boiling? What are 
the characteristics of yellow elastic tissue? Sketch. See Fig. 12. 

Stained Yellow Elastic Tissue. A portion of the ligamentum 
nuchas was hardened in alcohol, stained in borax-carmine, im- 
bedded in celloidin, and sectioned longitudinally. Remove from 
the oil and mount in balsam. Study and sketch under high power. 

Stained Yellow Elastic Tissue. The above was repeated for 
a cross section. Study under high power, noting the grouping 
into bundles and the angular shape of the fibers. Do you find 
any cells? Sketch a small portion as seen under the high power. 

Areolar Connective Tissue. With your fine forceps remove 
a portion of the subcutaneous tissue of a cat or rabbit and place 
on a dry slide and, if the ends are drawn out and the center kept 
moist by breathing upon it, a thin film may be obtained which 
should be covered with a cover-glass having a drop of salt solu- 
tion upon it. The tissue may be teased in the salt solution but it 
is less satisfactory than the above method. Study under high 
power. How is the white fibrous tissue arranged? Note the 
arrangement of the elastic fibers. Sketch a portion of the field 
and label the parts. Add dilute acetic acid as above and note the 
effect upon the different tissues. Can you distinguish fixed con- 
nective tissue cells? Sketch a portion of the field so as to show 
the different tissues. 



2 4 



A LABORATORY GUIDE IN HISTOLOGY. 



Embryonic Connective Tissue. A portion of human umbili- 
cal cord was hardened in formalin, imbedded in celloidin, and 
sectioned. Stain your section in hematoxylin and eosin, dehy- 
drate, clear, and mount in balsam. Study under high power. 
Note the branching connective tissue cells. Do they anastomose? 
Do you find any intercellular substance? Do you find fibers? 
Cross sections of blood vessels will be seen, but do not study 
them. Sketch a portion of the field showing form and relation of 
the cells. 

Fat Cells. The fatty mesentery of a dog was pinned to cork, 
fixed in alcohol, stained in hematoxylin, washed in tap-water, 
dehydrated, and cleared in oil of bergamot. Mount in balsam. 
Study under low power. The fat cells are clear and round or 
oval. How are they arranged? What is their relation to the 
blood-vessels? Sketch a group of the cells. Search for nuclei, 
using the high power. Sketch a typical cell. 



Cartilage. 

Hyaline. The larynx of a rabbit was fixed in corrosive sub- 
limate, hardened in alcohol, and imbedded in celloidin. Transfer 




the sections to water and stain in hematoxylin and eosin, dehy- 



drate, clear, and mount in balsam. 



A LABORATORY GUIDE IN HISTOLOGY. 



2K 



Study under high power. What is the character of the matrix? 
What is the shape of the cells? Do they occur singly "or in 
groups? Can you discern capsules around the cells? What is 
the structure of the perichondrium? Note the change in the size 
and shape of the cells as you pass from the perichondrium toward 
the center of the cartilage. Make a sketch. See Fig. 13. 

White Fibro-cartilage. A portion of fibro-cartilage was 
fixed in corrosive sublimate, hardened in alcohol, and imbedded 
in celloidin. Stain the section deeply in hematoxylin and then in 
Van Gieson's stain, dehydrate rapidly in 95% alcohol to which a 
small amount of concentrated solution of picric acid has been 
added, clear in oil of origanum, and mount in balsam. 

Study carefully using the high power. What is the compo- 
sition of the matrix? Are the cartilage cells encapsulated? Do 
you find any hyaline cartilage around the cells? Why is this? 
Sketch a portion of the section 
showing the structural relations. 

Elastic Fibro-cartilage. The 

epiglottis was fixed in corrosive 
sublimate, hardened in alcohol, 
and imbedded in celloidin. Stain 
with picro-carmine or with the 
elastic tissue stain used by Harris ; 
stain for about 10 minutes, wash 
one minute in 1% nitric acid in 
60% alcohol, dehydrate with 95% 
alcohol, clear, and mount in bal- 
sam. How are the cells arranged? 
Are they surrounded by hyaline 
cartilage? How may the elastic 
tissue be recognized? What is the 
arrangement of the elastic tissue? 
Sketch a portion as seen under 
high power so as to show the form 
and the relation of the tissues. 




Glycogen in Cartilage Cells. 
Treat fresh cartilage with dilute 



Fig. 14. Long. Section of Meta 
carpal Bones of a Fetus : a, hyaline 
cartilage; b, interosseous muscle 
c, center of ossification. 



26 



A LABORATORY GUIDE IN HISTOLOGY. 






Lugol's solution, and 
glycogen may be 
found in the cartilage 
cells, stained a pecul- 
iar brown color, usual- 
ly described as mahog- 
any brown. Study and 
sketch a few cells 
showing glycogen. 

Calcification and 
Ossification of Carti- 
lage. The hand of a 
small human fetus 
was fixed in formalin, 
dehydrated, and im- 
bedded in celloidin. 

Fig. 14(a). Developing Bone, a, Periosteum; Stain with hematoxy- 
b, periosteal bud; c, primary marrow space; y _, • j 

d, subperiosteal bone; e, marrow tissue. lm anQ _ e ° S 1 n > ana 

mount in balsam. 
Study under low 
power. Note that 
there are well de- 
fined areas shown 
in a long bone. 
Where is hyaline 
cartilage found? Do 
you find perichon- 
drium or perios- 
teum ? The areas 
should appear as 
follows if taken in 
order from the ar- 
ticular surface to- 
ward the center : 

(a) Hyaline or ar- 
t i c u 1 a r cartilage. 

(b) An area in 

Which the cartilage Fi - "fti- Developing Bone. Part of preceding 
& more highly magnified, a, periosteal bud; b, mar- 
cells are somewhat row; c, cartilage trabecula. 




A LABORATORY GUIDE IN HISTOLOGY. 



27 




flattened and arranged 
in longitudinal rows, 
(c) An area in which 
the cartilage cells are 
greatly enlarged, per- 
haps distending the 
capsules, (d) An 
area in which the cells 
seem shrunken and 
showing degeneration 
of the nuclei, (e) Area 
o f ossification i n 
which the primary 
marrow Spaces are to Fig. 14(c). Transverse Section of Rib of Fetus. 
be seen, as well as cal- ^Periosteum; b subperiosteal bone; c, trabecula 

of bone ; a, osteoblasts ; e, marrow, 
cified cartilage trabe- 
cule around which the osteoblasts are depositing layers of spongy 
bone. Sketch a portion so as to show a portion of each area in its 
relation to the other areas. See Fig. 14, Fig. 14(a), Fig. 14(b), 
and Fig. 14(c). 

Bone (Os). 

With the saw make thin transverse sections of a dry, clean 
metacarpal bone. Smooth one surface by rubbing on a fine file and 
then polish it on a fine hone. Using printer's paste or glue, fasten 
the sections on a smooth pine stick, allow the paste or glue 

to dry and then 
file the sections 
thin enough 
that the grain 
of the wood is 
e a s i 1 y seen 
t h r o u g h the 
s e c t i o n. Re- 
move the sec- 
tions by soaking 
in warm water. 
dry and polish 
* * "* * - — ■ -*" *+J^\ on a tine hone. 

Fig. 15. Transverse Section Bone. (7, Haversian canal; rubbincr until 
surrounding a are the lamellae ami the lacunae. The 
canaliculi are shown connecting the lacunae. Sin examination 




28 A LABORATORY GUIDE IN HISTOLOGY. 

under low power shows the structures clearly. When perfectly 
dry mount on a slide in the following manner: Place a little very 
thick balsam on a slide and a little on a cover-glass. Heat the slide 
and cover carefully, and cool until a film forms, place the section 
on the slide, cover quickly, and press cover down firmly. 

Study the transverse section first under low power and then 
under high power. The Haversian canals with the concentric 
lamellae of bone surrounding them are easily recognized. What 
is the nature of the matrix? Study the outer and inner circum- 
ferential lamellae. Do you rind Volkmann's canals? Note the 
interstitial or intersystemic bone between the concentric Haver- 
sian systems. What is the position of the lacunae? Do the 
canaliculi anastomose? Do the canaliculi of the adjacent systems 
anastomose? Do the Haversian canals anastomose? Sketch a 
portion under high power. See Fig. 15. 

Teeth (Dentes). 

1. Prepare a transverse section of the fang of an incisor or 
canine tooth by the method previously described for the prepara- 
tion of bone sections. The section should be ground evenly and 
very thin, using great care that the section be not broken. Instead 
of using a file, the section may be ground on an emery wheel 
having a fine, smooth surface. Mount in hard balsam as directed 
for bone and label. Study under low power, noting the size and 
shape of the root canal, and the relative proportion of dentine 
and cementum. Make a sketch to show these things. Study the 
dentine carefully using a high power. Note the branching of the 
dentinal tubules as they radiate from the inner margin of the 
root canal. Do you find any uniformity in the branching of the 
tubules? Study the cementum. Do you find any Haversian 
canals? Does the structure of the cementum differ in any way 
from that of bone? Draw a "V" shaped section under high 
pOAver so as to show the details of structure. 

2. Prepare a longitudinal section in the same manner from 
the crown of an incisor tooth. Study the enamel carefully using 
both low and high power, noting the relative thickness of enamel 
and dentine. Hoav does the course of the enamel rods com- 
pare with that of the dentinal tubules? Do the enamel rods 



A LABORATORY GUIDE IN HISTOLOGY. 



29 




extend entirely through the thickness of the enamel? Explain 
the difference observed between the central and the peripheral 
portions of the enamel. 

3. The jaw of a young kitten or dog was placed in a mixture 
composed of 10% formalin 1 part, and 10% nitric acid 1 part, 
until the bone was decalcified when pieces were imbedded and 
sectioned transversely 
and longitudinally. Fair 
sections may be made 
without imbedding as the 
pieces may be held in the 
microtome clamp. Stain 
the sections in hematoxy- 
lin and eosin, and mount 
in balsam. 

Study the transverse 
section of tooth and jaw 
under low -power begin- 
ning at the center. What 
is the nature of the pulp? 
Surrounding the pulp and 
intimately connected with 
it by means of processes 
are the odontoblasts, cells 
columnar in form. 

Next in order is the 
dentine composed of den- 
tinal tubules tying in the intercellular substance or matrix, 
they branch? Do the lateral processes anastomose? 

Next in order is the granular layer of Tomes with its inter- 
globular spaces. What causes these spaces? Are they found in 
this situation in all parts of the tooth? 

Next in order is the cementum. How does it differ in ap- 
pearance from the bone you studied? From what does it de- 
velop ? 

Next in order is the dental periosteum. What is its struc- 
ture? From what" does it develop? Draw the section under low- 
power. 

4. Study your longitudinal section of tooth and jaw in the 




Fig. 16. Transverse Section Jaw and Teeth 
of a Cat. a, bone of a jaw; b, dental peri- 
osteum ; c, cementum ; d, dentine ; e, pulp ; 
f, odontoblasts. 

Do 



30 



A LABORATORY GUIDE IN HISTOLOGY. 



same manner. Many sections will show the permanent tooth 
beneath the temporary. If so, study their relations. This section 
is designed to show the enamel and its relations and should be 
carefully studied. Make a sketch under low power showing the 
general relations. 

5. The Enamel Organ and Tooth Cord of a Developing 
Tooth. If suitable human material is not accessible, embryos of 
cats, dogs, or pigs make suitable material for this purpose. Por- 
tions of the jaw of suitable 



>>;. 



n mm 





& 



size were fixed in mercuric 
chloride, treated with iod- 
ized alcohol, dehydrated 
in alcohol, imbedded in 
celloidin, and sectioned. 
The sections were stained 
in hematoxylin and eosin 
and cleared in phenol- 
xylol. Mount the section 
from the oil in balsam. 
Study under low and then 
under high power. Note 
the tooth cord connecting 
the enamel organ with the 
oral epithelium. Do you 
find the enamel organ for 
the permanent tooth? 

Fig. 17. Developing Tooth x40. a, oral epi- Note the beginning of the 
thelium ; b, tooth cord; c, enamel organ of * . ; , c , , 

permanent tooth; d, enamel organ of tern- formation Ot tne Qental 
porary tooth; e, dental papilla. papilla. Note carefully its 

relation to the enamel organ. Sketch carefully under low power 
showing the general features of the section. See Fig. 17. 

6. The Development of Dentine and Enamel. Sections 
were prepared as above from material showing later stages in 
the development of the tooth. Study first the enamel organ of the 
temporary tooth. Note the parts, inner enamel cells or adamant- 
oblasts and the outer enamel cells and the enamel pulp. What 
is the function of the enamel pulp? Note that the dental papilla 
is capped by the enamel organ, and that there is no development 



A LABORATORY GUIDE IN HISTOLOGY. 



3i 



of the fang. Study the enamel formed and describe it fully. How 
does the fang develop? Do you find the dental sac? This sac 
later becomes the dental periosteum or peridental membrane and 
forms a common periosteum for the tooth and the alveolus of the 
jaw. At the surface of the dental papilla the cells, odontoblasts, 
are arranged in a single layer. Study them carefully under the 
high power. Study the dentine. Where is the layer of dentine the 




Fig. 17(a). Developing Tooth x60. a, enamel 
organ ; b, dental papilla ; c, dental sac ; d, odonto- 
blasts ; e, enamel ; f, dentine. 

thickest? Observe carefully the junction of dentine and enamel. 
Study the dental papilla. Of what kind of tissue is it composed? 
Are vessels and nerves present? Study the relations of the de- 
veloping tooth to the jaw as it develops. Make a drawing of the 
tooth under low power and show all of the parts. See Fig. 17(a). 



Muscle (Musculus). 

Fresh Striated or Skeletal, (a) Tease a portion of the 
thigh muscle of a frog in physiological normal salt solution 
to isolate the fibers, and study under low and high powers. 



32 



A LABORATORY GUIDE IN HISTOLOGY. 



Do the fibers show striae. Do you find the sarcolemma? 
Broken fibers usually show the sarcolemma. Add a little 
dilute (.75%) acetic acid at the edge of the cover-glass and 
draw it under by holding filter paper at the opposite side. 
Where are the nuclei located? Do you find fibrillar? Make 
a sketch to show the sarcolemma in a broken fiber. 

(b) Tease the muscle of Hydrophilus, Avhich has been 
fixed in alcohol, in dilute glycerin on a slide, cover, and study 
under high power. This preparation shows the details of 
striation better than most preparations. Sketch a few fibers. 

(c) Longitudinal Section Human Striated Muscle. 

Stain the section in hematoxylin and eosin and mount in 
balsam. Study under both powers and sketch a small portion 



^i\\WVVX'b\,\XW\,. 




WNu^ 



cA&KWn 



v iA60\\\u.'j\wW\,, 



V\OAV"t<>, A^ U v\\\A^^V % 100. 

under high power. Where are the nuclei located? How are 
the fibers held together? What makes the longitudinal 
striations? Are the cells uni-nucleated or multi-nucleated? 
See Fig. 18(a). 

(d) Longitudinal Section of Injected Muscle. The 

muscle of a cat injected with carmine-gelatin was imbedded 
in celloidin, after hardening in alcohol, and sectioned longi- 
tudinally. Study and sketch under low power showing the 
injected vessels and their relation to the fibers. 



A LABORATORY GUIDE IN HISTOLOGY. 



33 



(e) Transverse Section Human Muscle. Tissue was 
fixed and hardened in alcohol, imbedded in celloidin, and 
sectioned. Stain the section in hematoxylin and eosin and 
mount in balsam. Study under low and high power. What 
is the position of the nuclei? What are Cohnheim's areas? 
Study the connective tissue of the muscle and the fibers. 
Sketch a small portion of the field under the high power. 
See Fig. 18. 

(f) Ranvier's Method Showing the Junction of Tendon 
and Muscle. Kill a frog by pithing brain and cord and place 
it immediately in about a liter of water heated to 55-6o°C. 




Fig. 18(a). Long. Section Striated Muscle. 

Leave it in the water for fifteen minutes, the water mean- 
while gradually cooling. The muscles are now readily sep- 
arated into bundles. With sharp scissors cut a longitudinal 
shred from the junction of the muscle and tendon. Tease 
this shred carefully on a slide in a drop of water, or in a 
drop of iodized salt solution, cover and examine. Note the 
retraction of the muscle substance from the sarcolemma 



34 A LABORATORY GUIDE IN HISTOLOGY. 

sheath. Xote the attachment of the sarcolemma to the ten- 
don fibers. Draw. 

Cardiac Muscle. (a) Macerate cardiac muscle for 
twelve to twenty-four hours in fuming nitric acid of 20% 
strength. Wash out the acid in water and shake the muscle 
vigorously in a long test-tube, or tease gently on a slide, and 
study under high power. What is the shape of the cells? 
Do they branch? Are they striated? W nat is the form and 
number of nuclei? Sketch two or three cells. 

(b) The heart of a cat was fixed in bichloride of mer- 
cury, hardened in alcohol, imbedded in celloidin. and sec- 
tioned. Stain in hematoxylin and eosin. Study under low 
and high powers. Do the bundles of fibers anastomose? 
What is the position of the nuclei in cross sections? 

Nonstriated Muscle, (a). Isolated Cells. — Macerate 
and study as above for cardiac muscle. Make a sketch to 
show form and structure of the cells. 

(b) Study the arrangement and appearance of non- 
striated muscle in section by using the intestine of Necturus 
which has very large cells. Sketch a portion under high 
power showing longitudinal and transverse sections of mus- 
cle. See Fig. 8a. 

Blood. 

Fresh Human Blood. Obtain a small drop of blood by 
pricking the finger on the dorsum just below the root of the nail, 
or on the volar surface just back of the tip of the finger. The 
finger should be cleansed carefully and washed with alcohol, and 
the needle should be sterilized by holding it in a flame. Place a 
drop of blood on a clean slide and cover quickly with a clean 
cover-glass ; mix a second drop of blood with a drop of physio- 
logical normal salt solution and cover ; place a larger drop of 
blood on a third slide and allow clotting to commence before 
adding the cover slip. The slides and cover-glasses for this work 
should be cleaned by washing in acid-alcohol to remove all traces 
of dirt and grease. The majority of failures to secure good 
preparations in blood work are due to lack of care in preparing 






A LABORATORY GUIDE IN HISTOLOGY. 



35 



the slides and cover-glasses. Study the first preparation, noting 
that the red corpuscles tend to collect in rouleaux. Search care- 
fully for white corpuscles. Make drawings to show the rouleaux 
and the relative size of the white and red cells, also sketch a red 
corpuscle as seen on edge. 

Examine the second preparation, noting any differences in 
appearance. Do the red cells collect in rouleaux*? Why? Keep 
this second slide as near 40° as possible and try to get a series of 
sketches showing the amoeboid movement of the white cells. 

The third preparation should be examined under low power 
and then washed gently with water to remove as many of the 
red cells as possible. The section may now be examined un- 
stained, or it may be stained with methylene blue. How are the 
fibrin threads arranged? Do they take the stain? The nuclei of 
the white cells should be stained a deep blue. Make a sketch to 
show the arrangement of the fibrin and of the cells. 



S ^OVv\vvwu^oX\^\kto^>^M 




\0<L\W>, 



Oq"q 



*y 



Xn&ow**^ 








Stained Human Blood. (1) Spread a drop of blood between 
two clean cover-glasses and quickly draw them apart and let the 
film dry. Place this cover-glass in the forceps and fix the film 
by passing quickly through the flame. Stain in hematoxylin and 
eosin, dry carefully, and mount in balsam. The nuclei of the 
white cells stain with the hematoxylin while the eosin stains the 



36 A LABORATORY GUIDE IN HISTOLOGY. 

protoplasm of the corpuscles and more deeply the eosinophile 
granules of the polynuclear cells. Examine with high power, 
noting the following forms of cells : 

(a) Erythrocytes stained with eosin. 

(b) Small lymphocytes, mononuclear, nucleus relatively 
large and staining deeply, small amount of protoplasm sur- 
rounding the nucleus. 

(c) Larger mononuclear cells having a nucleus which 
stains less deeply than (b). 

(d) Transitional forms with L T shaped nucleus. 

(e) Polynuclear cells with nuclei separate or lobulated 
and joined by fine threads of nuclear material. The nuclei 
stain quite deeply in most instances. Make drawing to show 
the various forms as seen under high power. See Fig. 19. 

(2) Make a second preparation of blood on the slide. To 
do this remove a small drop of blood from the finger with the end 
of a second slide. Hold the end of this second slide on the first 
at an angle of about 30°. As soon as the drop runs along the end 
of the second slide, draw it along on the first so as to leave a thin 
film of blood on the first slide. Some parts of this film will prob- 
ably be too thick for study, but other parts will be found where 
the cells will be arranged in a single layer. 

You will probably succeed in getting a better preparation 
in this way than by the use of the cover-glasses. Allow the film 
to dry in the air for a moment and then place the slide on end in 
a water-glass containing a few drops of pure formalin. Cover and 
allow the vapor of the formalin to act upon the film for ten min- 
utes. Dry the slide for a minute or two in the air and stain in a 
Strong alcoholic solution of eosin for five or ten minutes. Rinse 
slide with water and stain from two to five minutes in methylene 
blue. Wash with water, drain on a blotter, dry quickly in the air 
or near a flame, mount in balsam, and label. Study as above, 
comparing the result obtained with this method as compared 
with the dry method used above. Preparations may be made by 
treating the film with equal parts of ether and absolute alcohol 
for five or six hours and then staining as above, but for general 
work, with ordinary stains, the formalin vapor is greatly to be 
preferred. 



A LABORATORY GUIDE IN HISTOLOGY 37 

(3) Make a blood film on a clean slide and without previous 
fixation stain in Wright's stain as follows: With a wooden 
toothpick or small stick draw a light line of vaseline across the 
slide at the end of the blood film. This will prevent the spread- 
ing of the stain over the ends of the slide. Cover the film with 
Wright's stain and allow it to act for one minute. Dilute the 
stain on the slide with distilled water until a metallic film appears 
on the surface. This will require ten or twelve drops of water. 
Allow this diluted stain to act for four or five minutes and wash 
film in water until it has a pinkish tint. This should require 
about fifty or sixty seconds. Dry carefully between pieces of 
clean filter paper and when dry study as above. This stain is one 
of the best we have for making a differential count. 

Frog or Turtle Blood. (1) Make cover-glass preparations, 
fix in the dry way, and stain with hematoxylin and eosin. Make 
drawings showing the nucleated red cells and the relative size of 
white and red cells. 

(2) Study the amoeboid movement of the white cells. Ring 
a cover-glass with vaseline -and use it to cover a drop of blood 
mixed with a drop of normal salt solution. Find a white cell 
showing amoeboid movement and make six drawings, at two or 
three minute intervals, showing the changes in form. Can you 
distinguish ectoplasm and endoplasm ? Are the pseudopodia clear 
or granular? 

Bird Blood. Make and stain preparations of the blood of the 
English sparrow and study as above. It would be well to make 
drawings showing form and relative size of the erythrocytes of 
the various forms of blood that you have studied. 

Hemin or Teichmann's Crystals of Human Blood. Place a 
drop of blood on a slide, add a crystal or two of common salt, and 



-1 



g * allow the blood to dry. When dry add 



a few drops of glacial acetic acid. Cover 

{ / J^p a with a cover-glass and boat gently over 

m i? I * g a flame until the acid bubbles. Care 

smm ^S I should be taken that too great a degree 

r? i\ • c \\ °^ ncat ^ )e not use< 3 or the hematin may 

5 ^ be decomposed and the reaction will fail. 

The active boiling drives off the free HCl produced by 



38 . A LABORATORY GUIDE IN HISTOLOGY. 

adding the acetic acid. Cool and irrigate with water, or allow the 
acid to evaporate, and when perfectly dry mount in balsam. 
Study and make drawings of the brownish-black crystals, noting 
carefully their form, size, and arrangement. See Fig. 20. 

Hemin Crystals of the Sparrow. Prepare as above and com- 
pare carefully with those from human blood. Show the difference 
and also resemblance by means of sketches. 

Hemin Crystals of Cat, Dog, and Rat. Prepare and study 
as above. 

Hemin Crystals from Blood-stained Cloth. The portion of 
the cloth which you will receive has -upon it dried blood which 
should be prepared as follows : Tease it on a slide in normal salt 
solution, or in distilled water, add a few crystals of salt and set 
aside until the stain soaks out into the solution. Now remove the 
fibers and let the solution evaporate. The evaporation may be 
hastened by gentle warming ; when dry add glacial acetic acid and 
finish the preparation as above. Examine carefully and try to 
identify the crystals. You will remember that this test is only to 
show that blood is present, as the crystals from pigeon's blood 
have much the same form and size as those of a mammal. Hemin 
crystals are chlorides of hematin, an iron compound found in the 
hemoglobin. The only test that is thoroughly reliable is the bi- 
ology test so called. This test is based upon the fact that when 
an animal is injected with blood serum from another animal a 
specific precipitin is produced in the blood of the animal so in- 
jected. For example, if a rabbit be inoculated with human blood 
serum a specific precipitin is developed in the rabbit's blood 
which will produce precipitation when introduced into human 
blood serum, but will precipitate no other blood serum. In other 
words precipitation only occurs in homologous sera. 

Hemoglobin Crystals. Collect several drops of blood in a 
small tube and wash thoroughly with sufficient distilled water to 
dissolve out the hemoglobin. Allow the corpuscles to settle, pour 
off the supernatant fluid and evaporate it slowly and carefully un- 
til it crystallizes. Dry carefully and mount the crystals in bal- 
sam. Study and draw under high power showing as many differ- 
ent forms as possible. 



A LABORATORY GUIDE IN, HISTOLOGY. 



39 



Study of Blood-Clot. Take a portion of the blood-clot given 
you, place it on a slide and cover with a 30% solution of potassium 
hydrate until the clot softens when it is to be teased and examined 
for corpuscles. Can you identify them? Do they belong to bird, 
mammal, or amphibian? Hand a written report of your findings 
to the instructor. 



Red Marrow of Bones. From the red marrow of the bone of 
a cat or dog make several cover-glass preparations. Fix one by 

■$y m ~ 




vWW. 



(XYvYtt 



How do the marrow cells 



* x x 0Y\\ 



the dry method and 
stain in hematoxylin 
and eosin. Fix another 
in formalin vapor for 
ten minutes and stain 
in methylene blue and 
eosin. Fix one in equal 
parts of ether and abso- 
lute alcohol for twenty- 
four hours and stain in 
hematoxylin and eosin. 
Mount in balsam. Study 
under high power and \\<v X\.CAV 
make sketches of the ^ 
various kinds of cells that you find, 
differ from leucocytes? 

(a) Search for erythroblasts having large nuclei with 
distinct chromatin threads, sometimes showing a tinge of 
color in the protoplasm. 

(b) Look for normoblasts having hemoglobin with 
globular deeply stained nuclei and no chromatic filaments. 
What becomes of the nuclei as the cells are transformed into 
erythrocytes? 

(c) Look for mononuclear eosinophile cells and trans- 
itional eosinophile cells. 

(d) Search for polynuclear cells and lymphocytes. 

(e) Try to find giant cells with polymorphous and sim- 
ple nuclei. See Fig. 21. 

Red Marrow in Sections. Split one of the long bones of a 
young child or a young animal. Place the split bone in Muller's 



40 



A LABORATORY GUIDE IX HISTOLOGY. 



fluid, or better, in formalin-Muller's fluid, and fix for twelve to 
twenty-four hours. Wash in water, harden in alcohol, dehydrate, 
and imbed the marrow in celloidin. Stain sections in eosin and 
methylene blue, and mount. Study and sketch typical marrow 
cells. Compare with the preceding preparation. 



Blood Vessels. 

The aorta of a dog was fixed in formalin, hardened in alcohol,, 
and imbedded in paraffin. Fasten a section to a slide with albumin 
fixative, remove the paraffin, stain in hematoxylin and eosin, and 
mount in balsam. Study under low and high power. Three coats 
or tunics should be found from the outer to the inner as follows : 

(i) The tunica adventitia which is not very thick. Y\ nat is 
its composition? How are the elastic fibers disposed? 

(2) The tunica media or middle coat consists largely of 
elastic tissue in concentric layers with very few smooth muscle 
cells. The tunica media is separated from the tunica intima and 

the tunica adven- 
titia by what are 



5 /^\\Oq\\\AWa. 







V, 



oax A i>.^^ uy\\^\i 






known as elastic 
limiting mem- 
branes. Do you 
find these mem- 
branes? AYhat is 
their structure? 

(3) The tun- 
ica intima consists 
of a single layer of 
flattened endothe- 
lium, the nuclei of 
which project in- 
to the lumen of 
the vessel, and a 
sub- endothelial 
fibrous layer rich- 
er in cells in the 



inner than in the outer portion next to the internal elastic limit 
ing membrane. 



What kind of fibrous tissue do vou find in the 



A LABORATORY GUIDE IN HISTOLOGY. 



4i 



intima? Sketch a portion of the vessel and label the parts. See 
Fig. 22. 

Medium Sized Vein. Stain the section in hematoxylin and 
Van Gieson's stain and mount in balsam. Study carefully under 
high power and sketch a section. The tunica intima consists of 
three layers : 

(1) A single layer of endothelial cells. 

(2) A layer of smooth muscle the bundles of which are 
somewhat separated by white fibrous connective tissue. 

(3) A fibro-elastic layer containing more white fibers 
than that of the artery. The tunica media, separated from the 
intima by an in- 



ternal elastic 
membrane, con- 
tains circularly ar- 
ranged muscle 
cells sometimes 
forming a contin- 
uous layer but 
often broken by 
strands of fibrous 
tissue. Compare 
with the media of 
an artery of the 
same size. The 
tunica adventitia 
has an inner longi- 
tudinal muscular 
layer which is us- 










<^c 



towv\ASs%v*.v o\ ft** 1 






ually quite prominent. The adventitia is thicker than in the 
artery and has a greater amount of the white fibrous tissue. 
See Fig. 23. 

Blood Vessels in Optical Section. The best material for this 

purpose is the pia mater of the brain. Fix the brain of a cat or 
dog in Midler's fluid or formalin-Midler's fluid for from twenty- 
four to thirty-six hours. Wash thoroughly in running water. 
Remove the pia mater with forceps and harden in alcohol, starl- 



ing with alcohol of a low grade, 35% 



Stain the thinner portions 



42 A LABORATORY GUIDE IN HISTOLOGY. 

in hematoxylin rather heavily, decolorize with 2% hydrochloric 
acid in 70% alcohol, wash in water, and stain deeply with eosin, 
dehydrate, clear, and -mount in balsam. Study carefully under 
low and high power. The veins are usually congested with 
blood which takes the eosin stain. The arteries have little blood 
in them and they will have a bluish tint. Between the smaller 
vessels the capillaries are to be found. Some will be filled with 
blood, the corpuscles usually being in a single row, while others 
will be empty with the walls collapsed. Trace the capillaries 
from the arterioles to the venules noting the changes that occur 
in the walls. Study carefully a precapillary artery and a small 
sized artery or arteriole. What changes occur in the structure of 
the walls? Make sketches to show the structure and relation of 
these vessels. 

Capillaries. Anaesthetize a cat and open the thorax. Open 
the left ventricle and remove as much blood as possible. Now in- 
ject a 1% solution of silver nitrate and after half an hour open the 
abdominal cavity, remove the mesentery and pin it out on sheets 
of cork and place in 10% formalin or 95% alcohol, and expose it 
to the sunlight until the tissue assumes a brownish tint. Dehy- 
drate, clear in oil of bergamot, or in Eycleshymer's mixture, and 
mount in balsam. The nuclei may be stained with hematoxylin 
if desired. Study under high power searching for capillaries and 
the smaller arterioles, the endothelial cells of which should be out- 
lined in browm or black lines. What is the shape of the cells? Is 
the outline regular or irregular? Do you find any intercellular 
spaces? Make a drawing. See Fig. 10. 

Adenoid or Lymphatic Tissues. 

Diffuse adenoid tissue is found in the mucosa of the intestinal 
and respiratory tracts as ill-defined masses of lymphatic tissue. 
Search for it in sections of larynx, stomach, and colon. The retic- 
ulum is usually partially or entirely obscured by the very numer- 
ous lymphoid cells. You may find it in places, however. Sketch 
a portion under the high power. The section of the appendix of a 
rabbit is excellent for studying diffuse adenoid tissue, though 
nodules are fairly defined in the submucosa.. 

Solitary Follicle or Nodule. Losing the low power, search for 



A LABORATORY GUIDE IN HISTOLOGY. 



43 



solitary follicles or lymphoid nodules in your section of the colon 
of a dog. Make a drawing to show the structure and relation to 
the surrounding tissue. See Fig. 24. 



atf*$ 






] *^ 
>•«$ 



IIP S»v4^. 



COv\t.t*\ 



ftvvA 



\\vv^v 



Fis 



24. A Solitary Lymph Nodule or Follicle from 
the Duodenum. 



Thymus Gland. Portions of the thymus gland were fixed in 
a saturated solution of corrosive sublimate in normal salt solution, 
hardened in alcohol, and imbedded in celloidin. Stain in hema- 
toxylin and eosin and mount in balsam. Study first under low 




power noting the fibrous capsule from which septa pass dividing 
it into lobules. The lobules are likewise divided into secondary 
lobules within which are the follicles of adenoid tissue. Note the 
difference between the cortical and medullary zones of the fol- 
licles. Search for the corpuscles of Llassal. What is their nature? 
How may they be recognized under the microscope? Sketch a 
follicle as seen under high power. See Fig. 25. 

Tonsil. Portions of the tonsil of a doe were fixed and hard- 



44 



A LABORATORY GUIDE IN HISTOLOGY. 



ened in alcohol, imbedded in celloidin, and sectioned. Stain in 
hematoxylin and eosin and mount. Study under low and high 
power noting the surface epithelium and the crypts lined with 
stratified squamous epithelium continuous with the surface epithe- 
lium. Do you find a leucocytic infiltration of the epithelium? 
Why do leucocytes invade this epithelium ? How is the lymphoid 
tissue arranged beneath the epithelium? Are "germ centers" 
present? Is the lymphoid tissue encapsulated by connective tis- 
sue? Look for portions of the retro-tonsillar glands. What type 
of gland do you find? Sketch a crypt and the underlying lym- 
phoid tissue, also the retro-tonsillar glands if they are present. 



A Lymph Node or Gland. A lymph node was fixed and 
hardened in alcohol and imbedded in paraffin. Fasten a section 

to the slide and 
stain in hema- 
toxylin and 
eosin. Some 
authors recom- 
m end Fie m- 
ming's solution 
a n d staining 
with safranin, 
especially for 
the study of the 
germ centers of 
the follicles. 
Study under 
low power, not- 
ing the connec- 
tive tissue cap- 
sule. What ele- 
ments enter into 
its c o m p o s i- 




Fig. 25(a). A Lymph Node x50. a, hilum ; b, capsule; 
c, primary trabecula. 



tion? Note that primary trabecule radiate toward the hilus from 
the capsule, thus dividing the cortex of the node into nodules or 
follicles. Note the secondary trabecular given off from the pri- 
mary. Tertiary trabecular are given off from the secondary 
which anastomose in the lymphatic cords. Look for lymph sin- 



A LABORATORY GUIDE IN HISTOLOGY. 



45 



uses between the capsule and cortical follicles and along the 
primary trabeculse. They also are found between the medullary 
cords and the trabeculse. What is the nature of the medullary 
substance? Draw under low power showing general relations. 
Study a follicle and its germ-center under high power and make 
a drawing showing the arrangement of the cells. See Fig. 25(a). 

Cells of Lymph Nodes. Make preparations by drawing the 
freshly cut surface of a node across the center of a clean slide. 
Fix in formalin vapor for ten minutes, or by heat, and stain in 
methylene blue and eosin. Dry and mount in balsam. Study 
under high power. Do you find lymphocytes? What varieties 
do you find? Sketch a cell of each type found. 

Hemolymph Gland or Node. A hemolymph node was taken 
from the sides of the great vessels, in the neck of a cow, and fixed 
in alcohol containing 5% of formalin. Stain the sections with 
hematoxylin and eosin, and mount. Compare the structure with 
that of a lymph node. How do they differ in structure? Make 
a sketch of a portion of the node showing the blood sinuses. 



Injected Spleen. 

The spleen of a 
cat was injected 
with carmine-gel- 
atin, hardened in 
alcohol, imbedded 
in celloidin, and 
sectioned. Dehy- 
drate, clear, and 
mount in balsam. 
Study under low 
power. How do 
the arteries end? 
Sketch under low 
power. See Fig. 26. 




Fig. 26. Portion of Injected Spleen of a Cat x90. 



4 6 



A LABORATORY GUIDE IN HISTOLOGY. 



Stained Spleen. Tissue from the spleen of a dog was fixed 
in a saturated solution of corrosive sublimate in normal salt solu- 
tion, hardened in alcohol, imbedded in celloidin, and sectioned. 
Stain in hematoxylin and eosin and mount in balsam. Study 
under low power. What is the composition of the capsule? How 



,CO^Svita 




is the frame-work of the gland formed? What are the Malpighian 
corpuscles? What is their relation to the arterioles of the splenic 
artery? What is the nature of the splenic pulp between the 
splenic corpuscles? Make a drawing showing the general struc- 
tural relations of the spleen. See Fig. 27. 

Study the spleen pulp under the high power. In the reticu- 
lum should be found the following varieties of cells: (1) ery- 
throcytes; (2) a few nucleated erythrocytes; (3) giant cells; 
(4) leucocytes, especially the mononuclear variety; (5) cells con- 
taining pigment probably derived from the hemoglobin of broken- 
down red cells. 

Nucleated Red Corpuscles in Spleen. The method of Dr. E. 
T. Williams gives good results. Take the fresh spleen of a hog 
and from the outer edge cut wedge shaped pieces which are 



A LABORATORY GUIDE IN HISTOLOGY. 



47 



drawn very lightly across the center of a clean slide making a 
thin smear. Fix for one minute in the following fluid : 

Corrosive sublimate .78 gram. 

Sodium chloride .28 gram. 

Distilled water 30 c. c. 
Stain in an aqueous solution of hematoxylin, and counter- 
stain in eosin. Dry and study without a cover-glass under high 
power. These preparations may be permanently mounted in 
balsam. Sketch a few erythrocytes, and erythroblasts if they 
are present. 

The Tongue (Lingua). 

The apex of the tongue of a rabbit was fixed in bichloride of 
mercury, hardened in alcohol, and imbedded in paraffin. Fasten 
the section to the slide, remove the paraffin, stain in hematoxylin 
and Van Gieson's 
stain, dehydrate rap- 
idly, clear in oil of 
cloves, and mount in 
balsam. 

Study under low 
power. What forms 
of papillae do you 
find? What kind of 
epithelium covers 
them? Do the cells 
covering the papillae 
meet at the edges or 
overlap ? Do you 
find a connective tis- 
sue within the papil- 
lae? Do you find any 
glands? Where are 
they located? Are they serous or mucous? Study the muscula- 
ture of the tongue. Is the muscle smooth or striated? How are 
the muscles arranged? Do you find any nerves? Sketch as seen 
under low power. 

Fungiform Papillae. Portions of the tongue of the dog con- 
taining fungiform papillae were fixed and hardened in alcohol. 










Vv 



0,. X4.\\kv\0s\\oxvv\ \ ^0\\0v. 



48 



A LABORATORY GUIDE IN HISTOLOGY. 



>\\\\A\ 



imbedded in celloidin, and 
sectioned. Stain in hema- 
toxylin and eosin, dehy- 
drate, clear and mount. 

Study under low power. 
Note the connective tissue 
core and epithelial cover- 
ing of the papillae. Do you 
find any taste-buds in the 
epithelium of the papillae or in that surrounding it? Sketch papil- 
lae as seen under low power. See Figs. 28 and 29. 







V^l^. \ .VW^\\uX^ods Xo^OsVM.. 




Fig. 30. T. S. Foliate Papillae of Rabbit x70. The taste 
buds extend through the epithelium of the papillae. 

Taste Buds. Portions from the tongue of the rabbit contain- 
ing foliate papillae were fixed, hardened, imbedded in paraffin, 
and sectioned at right angles to the folds. Stain in hematoxylin 
and eosin, after fixing to the slide and removing the paraffin, clear 
in oil of cloves and mount. Study first under low power. What 



A LABORATORY GUIDE IN HISTOLOGY. 



49 



is the location of the taste-buds? Do they extend through the 
epithelium? What type of glands do you find? What are they 
called? Sketch a portion as seen under low power. See Fig. 30. 

Study the taste buds under high power. What is their form? 
Are they completely surrounded by epithelium? Sketch and show 
as much of the structure as you can. 

Circumvallate Papillae. Portions of the tongue containing 
circumvallate papillae were hardened in alcohol, imbedded in cel- 
loidin and sectioned. Stain in hematoxylin and eosin, clear in 
Eycleshymer's mixture and mount in balsam. Study under low 
and high power as above and sketch as seen under low power, 
showing the structural features. 



Alimentary Tract. 



i=^r^eb>:.4- -Wi 




.t^V^N 






Xvvws^V 



<V\UCOV(X/. 



C\v^\Aoo< w\w^\e- 



t \sxv© v VY\wsO\t. 



'CO Y\V\«.t\\<0 i \ \«,S*AC. 



CEsophagus. The oesophagus of a dog was fixed in bichloride 

of mercury, hardened in alcohol, and imbedded in celloidin. Stain 



5o 



A LABORATORY GUIDE IN HISTOLOGY. 



the section in hematoxylin and eosin, dehydrate, clear in Eycle- 
shymer's mixture, and mount in balsam. 

Study under low power. What kind of epithelium do you 
find? Do you find a muscularis mucosae? Study the structures 
found in the tela submucosa. What kind of glands do you find? 
Study the muscular layers. Is the muscle striated or non-striated? 
Sketch under low power and show the parts and general relations. 
See Fig. 31. 

Cardiac Stomach at its Junction with the CEsophagus. Stain 
in hematoxylin and Congo red and mount in balsam. Study under 
low and high power. Note changes in epithelium from stratified 
to simple columnar. Do you find glands in the tela submucosa? 

If so, what kind? What kind of 
muscle do you find and how are cells 
arranged? Make a drawing of the 
epithelium at the junction of the oeso- 
phagus and stomach. 

The Stomach (Ventriculus) with 
Blood Vessels Injected. After in- 
jection through the aorta with car- 
mine-gelatin, the stomach of a cat 
was hardened in alcohol, imbedded 
in celloidin, and sectioned. The sec- 
tions are in clearing oil from which you will mount them in bal- 
sam. Study and sketch under low power, showing the arrange- 
ment of the 
blood vessels. 
See Fig. 32. 

Cardiac 
Olands. Por- 
tions of the car- 
diac stomach of 
a dog were fixed 
in corrosive 
sublimate solu- 
t i o n, hardened 
in alcohol, and 
imbedded in -^m^s~<m 

paraffin. F i x^ v * flfc CjOxWfcCaWvSfcTW* $>WoiW 
sections to ° 




Fig. 32. Section of the Mucosa 
of a Cat's Stomach injected. 







\xwaw;. 



A LABORATORY GUIDE IN HISTOLOGY. 51 

slide, remove paraffin, and stain in hematoxylin and Congo red. 
Clear in oil of cloves and mount in balsam. 

Study under low power to get the general structural rela- 
tions. What type of gland do you find? What is the nature of 
the tela submucosa? Do you find any glands in it? How are the 
muscular tissues arranged? Sketch a portion as seen under low 
power. 

Study the glands under the high power noting the chief cells 
and the parietal cells, oval in shape, with prominent nuclei, and 
stained with the Congo red. Sketch. See Fig. 33. 

Glands of Fundus. Stain sections in hematoxylin and Congo 
red. Study carefully under low and high power. Note carefully 
the structure of the tunica mucosa. What kind of epithelium 
lines the gastric crypts? Are the glands simple or branched? 
Study the chief and parietal cells. What is the relation of the 
parietal cells to the membrana propria? How does the secretion 
of the parietal cells enter the lumen of the gland? How does the 
number and position of the parietal cells compare with those in 
the cardiac glands? Are the gland cells in the active or resting 
condition? See Figs. 33(a) and 33(b). Look for the plexus sub- 
mucosus in the tela submucosa. Study the muscular and serous 
coats. Make a sketch under low power to show general structure 
and under high power to show structure of the glands. 



Pyloric Glands. Portions of stomach from the pyloric region 
were fixed in corrosive sublimate, hardened in alcohol, imbedded 



52 A LABORATORY GUIDE IN HISTOLOGY. 

in celloidin, and sectioned. Stain in hematoxylin and eosin, dehy- 
drate, clear in oil of bergamot, and mount in balsam. 

Study under low power. How do the ducts of the pyloric 
glands differ from those of the cardiac and fundus glands? How 
do the secretory tubules differ? Compare the muscular layer 
with that of the cardiac end. Do you find any goblet cells in either 
cardiac or pyloric sections? Sketch a portion under the high 
power to show the glandular epithelium and compare with the 
epithelium of the cardiac stomach. 

Active and Resting Glands. Figs. 33(a) and 33(b) illustrate 
the changes in the microscopical appearance of the gland cells 
during the functional changes occurring during digestion. Both 
dogs were kept under same conditions for forty-eight hours, with- 
out food. One was then killed and portions of the pyloric stom- 
ach were fixed, imbedded, sectioned, and stained. The results 
obtained are shown in Fig. 33(b). The cells are distended with 
zymogen granules, i.e., are in the resting condition. At the end 
of forty-eight hours the second dog was fed sponge which re- 




&w*,\ 



\V»W*. 



mained in the stomach for twelve hours thus mechanically stimu- 
lating the secretion of the gastric juice. After this period of time 
the dog was killed and pieces of tissue were treated as above. In 
this case, that of an active gland, but few zymogen granules were 
found and those only near the lumen, thus showing that the gran- 
ules disappear from the cell during activity, moving toward the 
lumen of the secreting tubule and helping to form the gastric 



A LABORATORY GUIDE IN HISTOLOGY. 53 

secretion. During the period of rest these granules are formed 
by the protoplasm of the gland cells. See Fig. 33(a). 




Fig. 34. Duodenum Showing the Duodenal and Intestinal 
Glands x70. 

Duodenum. Portions of the duodenum were fixed in bi- 
chloride of mercury, hardened in alcohol, imbedded in celloidin, 
and sectioned. Stain in hematoxylin and eosin and mount. Study 
under low power noting the coats and general relations. Do 
you find villi? Note the glandule inltestinales (Lieberkuhni) 
and the glands of the tunica mucosa. Find the duodenal (Brun- 
neri) glands in the tela submucosa. Are they of the serous or 
mucous type? Are they simple or compound? Tubular or sac- 
cular? Make a drawing using the low power so as to show the 
general structure. See Fig. 34. 

Injected Ileum of a Cat. The injection mass used was car- 
mine-gelatin and it was injected through the abdominal aorta. 



54 



A LABORATORY GUIDE IN HISTOLOGY. 



The intestines were hardened in 
and sectioned. The sections are 




Fig. 35. Injected Intestine of a Cat. 

ers the villi? Are goblet cells 
laris mucosae. Note the vessels 
for nerve cells in the submu- 
cosa, plexus submucosus 
(Meissneri), and between the 
muscular layers, plexus myen- 
tericus (Auerbachi). Do you 
find adenoid tissue? In what 
form does it occur? Note the 
tunica muscularis and the tun- 
ica serosa. What is the struc- 
ture of the tunica serosa? 
Sketch a portion under the low 
power. See Fig. 35(a). 

Colon. Portions of colon 
were fixed in bichloride of mer- 
cury, hardened in alcohol, and 
imbedded in paraffin. Fix the 
sections to the slide, remove the 



alcohol, imbedded in celloidin, 
in clearing fluid and are to be 
mounted in balsam. Study*and 
sketch under low power. See 

Fig. 35- 

Small Intestine Stained. 

Portions of the ileum were fixed 
in bichloride of mercury, hard- 
ened in alcohol, imbedded in 
celloidin, and sectioned. Stain 
in hematoxylin and Van Gie- 
son's stain, dehydrate quickly, 
clear in Eycleshymer's mixture, 
and mount in balsam. 

Study under low power. 
What is the shape and struc- 
ture of the villi?- Note the 
glandulae intestinales. Do they 
extend through the mucosa? 
What kind of epithelium cov- 
present? Study the muscu- 
of the tela submucosa. Look 




Fig. 35(a). Villi and Glands of the 
Ileum. 



A LABORATORY GUIDE IN HISTOLOGY. 



oo 



paraffin, and stain with hematoxylin and eosin. Mount in bal- 
sam and study under low power. Are villi present? What 
glands are found in the tunica mucosa? What kind of epithelium 
do you find? Are goblet cells present? Do you find diffuse 
adenoid tissue? Are solitary nodules present? How is the mus- 




Fig. 35(b). Colon of Man: a, Intestinal Glands; b, 
Tela Submucosa; c, Circular Muscle Layer; d, Longi- 
tudinal Muscle Layer; e, Muscularis Mucosae ; f, Blood 
Vessel. 



cular tissue arranged in the tunica muscularis? Sketch to show 
general structural relations and draw an intestinal gland under 
the high power. See Figs. 35(a) and 35(c). 

Vermiform Appendix. Portions of the appendix of a rabbit 
were hardened in alcohol, stained in Delafield's hematoxylin, and 
imbedded in paraffin. Fix to the slide, remove the paraffin with 
turpentine and xylol, and mount in balsam. Study and sketch 
under low power noting carefully the structural relations. I low- 
do the glands differ from those of the large intestine? What 
arc the structural characteristics of the appendix? 



56 A LABORATORY GUIDE IN HISTOLOGY. 




■ . 



f «V^ 






- 



Fig. 35(c). Transverse Section of the Glandular 
intestinales. 



Digestive Glands. 

Parotid. — Serous Type. Small pieces of the parotid gland 
were fixed and hardened in absolute alcohol and imbedded in 







A LABORATORY GUIDE IN HISTOLOGY. 57 

paraffin. Fix the section to the slide, stain in hematoxylin and 
eosin, and mount in balsam. Study under low power and note 
the lobules which are held together by connective tissue. Of 
what structures are the lobules composed? Do you find any 
intralobular ducts? Study the acini under the high power. Is 
the protoplasm clear or granular? Are the cells in the resting 
or active condition? Do you find a basement membrane? 
Sketch a portion under the low power to show the general rela- 
tions and a few of the acini under the high power to show the 
epithelium of the acini and a duct. See Fig. 36. 

Submaxillary Gland. — Mixed Type. The tissue was fixed 
in Flemming's solution, and imbedded in paraffin. Fix the sec- 
tion to the slide, and stain in Delafield's hematoxylin and Congo 
red. Dehydrate, ^^^_ u 

clear, and mount ^ WftuV v^\,7>^n^ . v \\ t 

in balsam. Study ifelSf^^ &\**«muu. 



first under low 




i - tOV\t\t^ *\\> i v***** 



power noting that \$WM\j$kW^ v *'9WZ •) ■'•/*• ^K 

the general struc- WMffi^^ 



YXVAXCOU* a^tvOWV. 



V\utXtu^ o\muto**\ t«W. 



ture is very simi- 
lar to that of the 

parotid gland. H^WUuWW 

Study the acini n c (\ \\ \ \\ 

under high power. ^ 3 1 -^^ ^ Stto H » VAtWs iW™ d»W»&Ux«£ 

Is a basement membrane present? Are the cells clear or granu- 
lar? What is the position of the nucleus? Look for the cres- 
cents of Gianuzzi or the demilunes of Heidenhain. What relation 
do they bear to the mucous cells of the acini? Are the cells of 
the crescents clearly defined? Sketch a small portion showing 
a duct, mucous acini and the crescents. See Fig. 37. 

The Sublingual Gland. Mucous Type. Portions of this 
gland were hardened in alcohol, imbedded in celloidin, and sec- 
tioned. Stain your section in hematoxylin and eosin, and mount. 
Study under low power comparing the general structure with that 
of the submaxillary and the parotid. Study the secretory acini 
under high power. Do you find a mucous or serous type of gland 
cell? Sketch a portion under high power to show structure of 
the acini. 

The Pancreas. Pieces of the pancreas of a dog were fixed 



58 



A LABORATORY GUIDE IN HISTOLOGY 



in bichloride of mercury, hardened in alcohol, and imbedded in 
paraffin. Fix the section to the slide, remove the paraffin, stain, 
and mount in balsam. 

Study under low power noting that the structure and gen- 
eral appearance is very similar to that of the parotid gland. 

Study the acini under the high power. Is the protoplasm 
clear or granular? What is the position of the nucleus? Is a 
basement membrane present? Do you find the centro-acinar 
cells? Do you find the areas of Langerhans between the acini 



\YVVlv\cto\Afr* t,OYNY\.\\' 



fttAYVUV 



vJUtW. 




\_> uv\Ci«.>c\\Uy\'b. 



of the gland? How do they appear in contrast with the acini? 
Do you find any traces of ducts in them? Sketch an area of 
Langerhans with the surrounding acini as seen under high power. 
See Fig. 38. 

The Liver (hepar) with Blood-Vessels Injected. The liver 
of a dog was injected through the portal vein with carmine- 
gelatin, hardened in alcohol, imbedded in celloidin, and sectioned. 
The sections are in clearing oil and should be mounted in balsam. 

Study under low power noting the lobules and their ar- 
rangement. Between the lobules are the interlobular veins. Of 
what are they branches? Study the capillaries of the lobule 
noting that they originate from the interlobular A^eins and that 
they pass into the capillaries of the vena centralis lobulse, the 
beginning of the hepatic system of veins. It is difficult to deter- 
mine where the capillaries from the portal vein cease and those 
of the hepatic vein begin. By searching the section you should 



A LABORATORY GUIDE IN HISTOLOGY. 



59 




be able to find 
where a vena cen- 
tralis lobulse pass- 
es into a sublobu- 
lar vein. Sketch 
under low power. 
See Fig. 39. 

Injected and 
Stained Liver. 

Portions of liver 
as injected above 
were stained in 
Delafield's hema- 
toxylin, imbedded 
in celloidin, and 
s e c t i o n ed. Re- 
move the sections 

from the clearing Fig- 39. Dog Liver Injected 

.« . , . b, vena centralis lobular ; c, 

oil and mount in 




Fig. 40. Pig Liver x90. The Lobules. Interlobular 
Connective Tissue, and Portal Canals arc shown 



a, interlobular veins ; 
branch of portal vein. 

balsam. Study as 
above, noting the 
relation of the 
hepatic cells to the 
capillaries, and 
sketch a small 
portion under 
high power. 

Stained P i g 
Liver. Small 
pieces of pig liver 
were hardened in 
absolute alcohol 
and imbedded in 
paraffin. Fix the 
s e c t i n to the 
slide, remove the 
paraffin, and stain 
i n hematoxylin 
ami eosin, clear in 



6o A LABORATORY GUIDE IN HISTOLOGY. 

oil of cloves, and mount in balsam. Study the lobules and gen- 
eral structure under low power. The pig's liver is well adapted 
for the study of the general structure since the lobules are very 
distinct. Find a portal canal containing a bile duct, hepatic 
artery, and portal vein. What is the position of the canal? Study 
the capsula fibrosa. Do you find lymphatic vessels in the canals? 
Draw a portal canal with portions of the adjacent lobules as 
seen under low power. See Fig. 40. 

Impregnated Liver. Oppel's Method. Pieces of liver were 
placed for three days in a solution consisting of four parts 3% 
solution of potassium bichromate and one part of a 1% solution of 
osmic acid, and were then placed in a £4 to 1% solution of silver 




V \a.Hl. &\\e Ccx«v\\fcvu«» twvt) "^naiXvY^o. 



nitrate where they remained several days, after which they were 
rapidly imbedded in celloidin, sectioned, and you will mount and 
study them in clearing oil. They may be mounted in hard balsam. 
The bile capillaries are stained black. Study their relations to 
the cells and sketch under high power. See Fig. 41. 

Gall Bladder (Vesica felleae). Stain sections of gall bladder 
in hematoxylin and eosin and mount in balsam. Study under 
low and high power. How many coats do you find? How do 
you distinguish them? Are rugae present? Give characteristics 
of the mucosa. How is the muscular tissue arranged? Do you 
find a tela submucosa between the mucosa and the muscularis? 
Is the tunica serosa complete? Sketch under low power. See 
Fig. 41(a). 



A LABORATORY GUIDE IN HISTOLOGY. 



61 




Fig. 41(a). T. S. Wall of Vesica Felleze. The Mucosa 
shows the Anastomosing Rugae. 

The Kidney (Ren). 

Kidney Macerated to Show Tubules. Place strips of the 
kidney of a cat or other animal in 25 to 30% hydrochloric acid 

w 



* lip 0§$ te*»o\vA «.k Ku.W\ 1 

•ft 

§1 I 



>\\ ttAvAoA^WV*,. 



. COWtc 



^\l»-\\KAC(C\O><V0N \vOou\t. 



V\a.H^. \vc\(x,w\^A«, o\ \v\V>\x\^b yv^Avu^ J\o^- 



62 



A LABORATORY GUIDE IN HISTOLOGY. 



for twenty-four hours after which wash one hour in running- 
water. Tease carefully and examine in 50% glycerin. The 
tubules will be broken up somewhat but by studying the prepa- 
ration carefully under low power the parts of the tubule may be 
found. Sketch and label as many parts as you can recognize. 
See Fig. 42. 

Kidney of a Cat Injected. The kidney of a cat was injected 

through the renal artery with carmine-gelatin, hardened in alco- 
hol, imbedded in celloidin, and sectioned. Remove the sections 

from the clear- 
ing oil and 
mount in bal- 
sam. 

Study under 
low power. Do 
you find por- 
tions of the ar- 
t e r i a 1 arch ? 
Note the 
straight arterio- 
lserectse extend- 
ing into the me- 
dulla. Trace an 
interlobular ar- 
tery from the 
arch into the 
cortex. Study 
the vasa affer- 
entia as the y 
terminate in the 
capillary loops, 
or glomeruli. 
Trace the vasa 




Fig. 43. Injected Kidney of a Cat x70. 



efferentia as they leave the glomeruli and form capillary net 
works about the convoluted portions of the tubuli uriniferi. Study 
the formation of the capillary network in the superficial part of 
the cortex. Draw under low power showing as many of these 
points as you can. See Fig. 43. 



A LABORATORY GUIDE IN HISTOLOGY. 



63 



Stained Kidney. A portion of the kidney of a cat was fixed 
in Carnoy's fluid for about five hours, the fluid was then washed 
out with absolute alcohol and the tissue was imbedded in cel- 
loidin, sectioned transversely, stained in iron-alum-hematoxylin, 
counterstained in ac- 
id-fuchsin, and the 
sections are now in 
clearing oil from 
which they are to be 
mounted in balsam. 

Study under low 
power noting the cap- 
sule and the division 
into cortex and me- 
dulla. 

Locate the medul- 
lary rays extending 
into the cortex from 
the base of the pyra- 
mid. Of what are they 
composed ? Locate 
the columnse renales 
(Bertini). What are 




Fig. 44. Human Kidney : a, glomerulus ; b, me- 
dullary ray ; c, convoluted tubules ; d, capsula 
glomeruli 



they and why are they present? What is the pars convoluta 
(labyrinth) ? Study the pyramids. Why do they have a striated 
appearance? Look for blood capillaries. Study the glomeruli. 
What is the relation of the glomerulus to capsula glomeruli? 
Sketch under low power to show the general structural relations. 
See Fig. 44. 

Study the glomeruli under the high power. Study the differ- 
ent portions of the tubules under high power noting the varia- 
tions in the character of the epithelium and sketch cells from 
each part to show the nature of the epithelium. Do you find a 
basement membrane? Study the capsule under high power. 
What is its composition? Notice the intertubular connective 
tissue, relatively small in amount in the normal kidney. Sketch 
a corpuscula renis (Malpighii) and a portion of the surrounding 
tissue as seen under high power. 



64 A LABORATORY GUIDE IN HISTOLOGY. 

Section of the Kidney of a Fetus. The kidney of a fetus was 
hardened in alcohol, imbedded in celloidin, and sectioned. Stain 
in hematoxylin and eosin, clear in Eycleshymer's mixture, and 




Fig. 44(a). Kidney of Fetus x80. Shows junction 
of two lobes and development of the kidney corpuscles. 

mount. Study as above, noting the development of the tubules 
and the relation of the glomerulus to the capsula glomeruli. 
Sketch a portion. See Fig. 44(a). 

Suprarenal Body (Glandula suprarenalis). 

The suprarenal body was hardened in alcohol and imbedded 
in paraffin. Fix the section to the slide, remove the paraffin, 
stain in hematoxylin and eosin, clear in oil of cloves, and mount 
in balsam. 

Study under low power. Study the capsule and septa pass- 
ing into the body. Note the division into cortex and medulla. 
Study the cortex noting the zones of which it is composed. The 
outer zone is known as the glomerular zone since the cells are 



A LABORATORY GUIDE IN HISTOLOGY 



65 



in groups separated by septa derived from the capsule. The 
middle zone has the cells arranged in columns or bundles of 
cells separated by the connective tissue and is called the fascicular 
zone. The inner zone is composed of anastomosing cords of cells 
and is known as the reticular zone. Note that medulla is 
composed of strands of cells usually pigmented and irregular 







•*l^< 



in shape. What is the nature of the spaces between the strands 
of cells? Study the blood vessels and nerves of the gland. Sketch 
a section under low power showing general structure. See Fig. 45. 

Bladder (Vesica urinaria) and Ureter. 

Collapsed Bladder. Pieces of bladder were fixed and hard- 
ened in alcohol, imbedded in celloidin, and sectioned. Stain in 
hematoxylin and eosin, clear and mount in balsam. 

Study under low power. What kind of epithelium do you 
find? How many layers of cells are present? llow do the cells 
of the various layers differ in form, and why do they so differ? 
Ts diffuse adenoid tissue to be found in the tunica mucosa' Do 



66 A LABORATORY GUIDE IN HISTOLOGY. 

you find glands in either the tunica mucosa or the tela sub- 
mucosa? How many muscular layers do you find in the tunica 
muscularis? Is the muscular tissue regularly or irregularly dis- 
posed? Do you find a tunica serosa? Study the section under 




Fig. 46. Contracted Bladder x90. 

high power and identify the structures fully, asking help of the 
instructor if necessary, and sketch a portion under the low power 
in order to show the relative thickness and relations of the layers. 
See Fig. 46. 

Distended Bladder. The bladder of a rabbit was distended 
with the fixing fluid and then placed in a quantity of the same 
fluid until fixed and hardened after which it was imbedded in cel- 
loidin and sectioned. Stain in hematoxylin and Van Gieson's 
stain, dehydrate quickly, clear, and mount. Study as above and 
compare the sections carefully noting the principal points of 
difference in the appearance. 

Ureter Near Pelvis. Tissue was prepared as for the section 
of collapsed bladder and you will prepare and study in the same 
manner. 

Ureter Near Bladder. The tissue was treated as above and 
the sections are to be stained and mounted. Compare the sec- 



A LABORATORY GUIDE IN HISTOLOGY. 



67 



tions of ureter, especially the musculature. What kind of con- 
nective tissue do you find? 



Male Reproductive Organs 
(Organa genitalia virilia). 

Testis. The testis of a rat was fixed in Flemming's solution, 
imbedded in paraffin, sectioned transversely, and fixed to cover- 
glasses. Remove the paraffin, stain in hematoxylin and eosin, 
dehydrate, clear in oil of cloves, and mount in balsam. Study 
under low powe r, 
noting first the cap- 
sula fibrosa or tunica 
albuginea which sur- 
rounds it. Trace the 
trabeculse from the 
capsule into the 
gland substance. 
Some fatty tissue 
may be found out- 
side the capsule. 
Study the sections of 
the tubuli seminiferi, 
some of which are 
cut transversely and 
some obliquely, not- 
ing the layers of epi- 
thelial cells forming 
the walls. Note the 
epididymis at one 

side of the section. How is the canal of it 
may be found stained black 
tion under low power to show the general relations. See Fig. 47. 

Study the tubules under high power. By moving the section 
tubules in different stages of development may be found. Study 
the intertubular tissue carefully. Do you find a distinct basement 
membrane? What is the nature of it? Within the membrane 
you find the layer of spermatogones and the base oi the support- 
ing cells of Sertoli. The second layer is that of the sperm mother- 




Fig. 47. Testis of a Rat, under low power : a, 
tubule cut longitudinally ; b, tubule cut transverse- 
ly; c, intertubular connective tissue. 

ined? Fat globules 
with the osmic acid. Sketch a por- 



68 



A LABORATORY GUIDE IN HISTOLOGY. 



cells or spermatocytes. Next in order are several layers of 
smaller cells, the spermatoblasts or spermatids, which become 
sperm cells without further division. Can you find spermatids 




Fig. 48. Single Tubule of Testis. The nuclei show 
light. Sperms are pointed arranged along the susten- 
tacular cells. 

that have fused with the cells of Sertoli? Study various tubules 
very carefully and sketch several to show as many of the stages 
in development as possible. See Fig. 48. 

Testis. Compare with the above sections prepared as above 
and stained in iron-alum-hematoxylin. Study the tubules of this 
section under high power as this stain is very satisfactory for the 
nuclear structures. 

Epididymis. Stain and mount sections from the parts of 
the epididymis. Study under low and under high power. The 
sections will probably show portions of the ductuli efferentes. 
Study the mucosa of the epididymis. Study the connective tissue. 
How are the coils of this structure held together? Make draw- 
ings showing these things. 

Ductus deferens. Prepare and study under low and high 



A LABORATORY GUIDE IN HISTOLOGY. 



69 



power. The ductus deferens is a continuation of the vas epididy- 
midis. Study the tunica mucosa. Is epithelium ciliated? Simple 
or stratified? Is the epithelium of the same type throughout the 




Fig. 48(a). T. S. Rete Testis showing lining epi- 
thelium and spermatozoa in the lumen of each. 

duct? Study the membrana propria. Study the lamina propria 
and note its relation "to the tunica muscularis. What is the struc- 
ture of the muscularis? What of the relative thickness of the 
muscular coat? Note the outer fibrous layer of the duct. Draw 
under low power. 

Penis. The penis of a clog was fixed and hardened in alcohol, 
imbedded in celloidin, and sectioned transversely. Stain in hema- 
toxylin and Van Gieson's stain, dehydrate rapidly, clear in Eycle- 
shymer's mixture, and mount in balsam. 

Study first under low power noting the three masses of 
erectile tissue. The corpora cavernosa have a strong, dense tunica 
albuginea surrounding them. The corpus spongiosum surrounds 
the urethra. Note the septa and trabecule derived from the 
tunica albuginea. What tissues are found in the sheath and 
septa? Do the spaces formed by the septa and trabeculae com- 
municate with each other? Are the spaces lined with endothe- 
lium? Note the blood vessels. Study the urethra. What kind oi 



7o 



A LABORATORY GUIDE IN HISTOLOGY. 



epithelium in it? Do you find any glands? Study the blood ves- 
sels of the submucosa and the muscular tissue of the urethra. 
Sketch as seen under low power and label the parts. See Fig. 49. 



y^P^\ 




Fig. 49. Transverse Section of the Penis of a Dog: a. urethral lumen; 
b, epithelium ; c, corpus spongiosum surrounding the urethra ; d, corpora 
cavernosa showing some ossification ; e, tunica albuginea ; /, blood vessel. 

Prostate Gland (Prostata). The prostate gland of a dog was 
fixed and hardened in alcohol, imbedded in celloidin, and sec- 
tioned. Stain in hematoxylin and eosin, dehydrate, clear in 
Eycleshymer's mixture, and mount in balsam. 

Study under low power. Notice the structure of the capsule 
noting the large proportion of smooth muscle in it. Study the 
trabecular framework. What type of gland do you find? What 
kind of epithelium, lines the tubule? Is it a serous or mucous 
gland? Is a basement membrane present? Find the duct empty- 
ing into the urethra. What kind of epithelium forms the lining 
of the duct? Sketch a portion under low power to show the 
general structural relations and a portion of a gland as seen under 
high power. See Fig. 49(a). 



A LABORATORY GUIDE IN HISTOLOGY. 7 i 




Fig. 49(a). Human Prostate x90. 

Cowper's Gland (Glandula bulbourethralis). Portions of the 
gland were fixed, hardened, imbedded in celloidin, and sectioned. 
Stain in hematoxylin and eosin, and mount in balsam. Study 
the general structural features under low power. What type of 
gland as to form? As to secretion? Are crescents of Gianuzzi 
present? What kind of epithelial lining do the ducts possess? 
Look for larger ducts lined by two or three layers of cells. Sketch 
a portion of the gland as seen under high power. 

Female Reproductive Organs. 

(Organa genitalia muliebria). 

Ovary (Ovarium). The ovary of a dog was fixed in Flem- 
ming's solution, hardened in alcohol, and imbedded in paraffin. 
Fasten the section to the slide, remove the paraffin, stain in hema- 
toxylin and eosin, clear in oil of cloves, ami mount in balsam. 

Study first using the low power. Note the division into the 



72 



A LABORATORY GUIDE IN HISTOLOGY. 




a\^ 



cortical and medullary portions. The larger vessels are found in 
the medulla. Study the germinal epithelial layer. The frame- 
work of the ovary is known as the stroma. What is its composi- 
tion? In the cortex you should 
find the Graafian follicles in 
different stages of development. 
The simple primitive follicle 
has but a single layer of epithe- 
lial cells surrounding the egg- 
cell and surrounded by stroma. 
Find such follicles. The fully 
developed follicle has a rather 
dense stroma, the theca folli- 
culi, surrounding it, and instead 

r> ^ A \ \ of a single layer of cells lining 

\^o._Cox^\^^xvvoo. it/it w f u h / ye seyeral Iayer g s 

forming the membrana granulosa. Can you distinguish the 
fibrous tunica externa of the theca? Note that this layer blends 
closely with the tunica interna which is more vascular than the 
externa and has 
more cells. One 
portion of this 
membrana 
granulosa b e- 
comes thick- 
ened forming 
the discus pro- 
1 i g e r u s sur- 
rounding the 
egg-cell. Some 
of the cells 
have- disappear- 
ed forming the 
antrum or cav- 
ity of the fol- 
licle, containing 
the liquor folli- 

C U 1 i. W hat Fig- 51. Ovary of a Cat x90. Above and below nearly 
,« mature follicles are seen. One follicle having two ova 

causes the pre- is shown . 




A LABORATORY GUIDE IN HISTOLOGY 



73 



cipitate found in the antrum in the sections? Study the various 
stages of development between the primitive follicle and the 
fully developed follicle. Do any follicles have more than one 
egg-cell? Do you find a corpus luteum composed of relatively 
large cells having small nuclei? If so, study carefully. See Fig. 
50. Make a sketch under low power so as to show the general 
features of the ovary and sketch several follicles under the high 
power to show the stages of development. See Fig. 51. 

Ovary of a Very Young Animal. The ovary of a young 
animal was treated as above. Stain in hematoxylin and eosin 
and mount. This is designed to show the development of the 
egg-tubes from the germinal epithelium. 

W\\* Wow\ o 



Y\^\<> 

iYV\Ov\"\X\\>\^ 




Y\tA (& tt\\% 






^Vj>W^ 



CvW 



Study under low and high power. Find a downward 
growth of cells forming the egg-tube. Note that it is simply a 
downward proliferation of the cells from the layer oi germinal 
epithelium into the stroma. Are all of the cells of the tube alike? 
Study other tubes and note that certain cells form the ova and 
others form the follicular epithelium surrounding them. Search 
for a tube which has been penetrated by connective-tissue septa 



74 



A LABORATORY GUIDE IN HISTOLOGY. 



so as to divide it into somewhat distinct epithelial nests. The 
connective tissue later forms the theca folliculi surrounding the 
follicle. Sketch a portion of the section showing as many of 
these points as possible. See Fig. 52. 

Fallopian Tube (Tuba uterina). Portions of the tube were 
fixed, hardened, imbedded in celloidin, and sectioned. Stain 
sections in hematoxylin and eosin and mount. Study under 
low and then under high power. What are the coats of the tuba 
uterina? What kind of epithelium is found in the mucosa? 
What is the structure of the fimbriae? How does the structure 
of the mucosa differ in the different parts of the tube? What is 
the structure of the tunica muscularis? How are the layers 
disposed? What is the relation of the inner circular fibers to 
the mucosa? Study the tunica serosa and its vessels and nerves. 
How are the vessels and nerves distributed? Make a drawing 
to show the general structure. 




Fig. 53. Uterus of a Dog. 

Uterus. Portions of the uterus were fixed in a saturated 
solution of corrosive sublimate in normal salt solution, hardened 



A LABORATORY GUIDE IN HISTOLOGY. 75 

in alcohol, imbedded in celloidin, and sectioned. Stain in hema- 
toxylin and Van Gieson's stain, dehydrate rapidly, clear in Eycle- 
shymer's mixture, and mount in balsam. 

Study under low and then under high power. How many 
layers do you find? What kind of epithelium in the mucosa? 
What is the nature of the tunica propria? Are glands present 
in the mucosa? Of what type are the glands? What kind of 
muscle in the tunica muscularis? How many layers? What do 
you find between the layers? Study the vessels of the tunica 
muscularis. Study the tunica serosa which presents the usual 
characteristics of serous membranes. Sketch a portion under 
low power. See Fig. 53. Study and sketch as much of a gland 
as possible as seen under the high power. 

Vagina. The vagina of a dog was fixed and hardened in 
alcohol, imbedded in celloidin, and sectioned. Stain in hema- 
toxylin and eosin, and mount in balsam. 

Study under low power. What kind of epithelium do you 
find? What are the characteristics of the tunica propria? Do 
you find any adenoid tissue in the mucosa? Are glands present? 
Do lymph nodules occur? Is a tela submucosa present? Study 
the tunica muscularis. Does it have distinct layers? Study the 
outer fibrous coat. Sketch as seen under low power so as to 
show the general structural features. Study under high power. 

Mammary Gland (Mamma). 

Portions of mammary gland were hardened in alcohol, im- 
bedded in celloidin, and sectioned. Stain in hematoxylin and 
eosin, dehydrate, clear, and mount. 

Study under low power. The lobules of the gland are com- 
posed of acini united by fibrous tissue. Search for and study 
the ducts. Study under high power. What variety of epithelium 
in the lining of the acini? What is the position of the nuclei? 
What do you find in the lumen of an acinus? How do you ac- 
count for the presence of fragments of epithelial cells? Study 
the epithelium carefully and then sketch a portion of the gland 
as seen under high power. 



76 A LABORATORY GUIDE IN HISTOLOGY. 



The Skin and its Appendages. 

Pieces of human skin were fixed in alcohol, and imbedded 
in paraffin. Fix the section to a slide, remove the paraffin and 
stain, one in hematoxylin and eosin, and one in hematoxylin and 
Van Gieson's stain, clear in oil of bergamot, and xylol, and mount 
in balsam. 

Study under low and high power. The layers of the epider- 
mis are as follows, beginning with the outer one: (i) Stratum 




Fig. 54. Transverse Section Skin from Heel x90. 
The layers are clearly shown and the duct of a sweat 
gland is shown opening between the papillary ridges. 

corneum or the horny layer. Are the cells well defined? Do 
they possess nuclei? (2) Stratum lucidum. Why so called? Of 
what form of cells is it composed? Is this layer granular? (3) 
Stratum granulosum. What is the form of cells? What is the 
nature of the granules in the cells of this layer? (4) A layer 
of stratified squamous epithelium the deepest cells of which are 



A LABORATORY GUIDE IN HISTOLOGY. 



77 



columnar in form. Note the transition in form of the cells as 
you go toward the surface. Why does the form of the cell 
change? 

Study the dermis noting its general structure. Can you 
distinguish the papillary and reticular layers? What is the gen- 
eral direction of the fibers in the pars reticularis? Note that the 
fibers of the pars papillaris are somewhat finer and hence the 
tissue is somewhat more dense than in the pars reticularis. Study 
the papillae. Study the glands of the skin under low and high 
power. Note their location and relations. Study the subcutane- 
ous tissue. Draw and label a portion of the section as seen under 
the low power so as to show general relations. Sketch a few 
tubules of the sweat glands as seen under high power. See 
Fig. 54- 

The Scalp. Portions of human scalp were hardened in alco- 
hol, imbedded in celloidin, and sectioned transversely. Stain in 



*/0\bVC*A\%. 



COVWXVA, 




^l^o^fcovxfe 0^0. xvV 
. Owv\ oil v**o\ 0^0^. 

i-WMX xoo\.£v>.to^- 

3L v oSW 



\\\S\x*. 



,QO<V 



hematoxylin and eosin, clear in Eycleshymer's mixture, and 
mount in balsam. 

Study under low power and then under high power paying 
especial attention to the hair and follicles and to the sebaceous 

glands. Sketch a hair and follicle as seen under high power, and 



78 A LABORATORY GUIDE IN HISTOLOGY. 





■*< 


pagfj^^ 


1 


1 JB 


.2 


> 

3& 


1 


k 










Fig. 56(a). Scalp of Fetus. 



A LABORATORY GUIDE IN HISTOLOGY. 



79 



label all the parts. See Fig. 55. Make a sketch of a sebaceous 
gland as seen under low power and. show its relation to the hair 
follicle. 

Fetal Scalp. Portions of fetal scalp were hardened in for- 
malin, imbedded in celloidin, and sectioned. Stain in hematoxy- 
lin and Van Gieson's stain, dehydrate rapidly, clear in Eycle- 
shymer's mixture, and mount in balsam. Study carefully, noting 
the development of the hair, glands, and the relation of the 
glands to the other structures of the scalp. Sketch a portion as 
seen under low power. See Figs. 56 and 56(a). 

Scalp Showing Hairs in Transverse Section. Portions of 
scalp were imbedded in celloidin and sectioned tangentially. 
Study the follicles under high power and note the layers. Note 
the division into cortical and medullary portions. Study each 
carefully. Study the layers of the root sheath. The inner sheath 




f(-fe r ^ 



V\0^o\. \.o. VWAOrtv y\a\V fcv\Wo\\"\<\c Ooo. 



has three concentric layers of cells; the inner cuticle surround- 
ing the hairs, the middle layer of Huxley composed of two layers 
of cells, and the outer single layer of clear cells or layer of 
Henle. The outer root-sheath has in its inner portion several 
layers of prickle cells composing the stratum Malpighii, the outer 



80 A LABORATORY GUIDE IN HISTOLOGY. 

layer of which is columnar in form. Next in order is the glassy 
membrane, then the circular connective tissue, and then comes 




Fig. 57(a). T. S. Hairs x90. 

the looser outer connective tissue with the bundles longitudinally 
placed. Sketch and label as seen under high power. See Figs. 
57 and 57(a). 

Development and Structure of the Nail. The thumb of a 
fetus was hardened in formalin, imbedded in celloidin, and sec- 
tioned longitudinally. Stain in hematoxylin and eosin, clear in 
oil of bergamot, and mount in balsam. Study the section under 
low power. See Fig. 58. Sketch. Study under high power 
remembering that the nail itself represents an enormously de- 
veloped stratum lucidum. Study the cells of the nail. The nail 
bed is composed of the stratum Malpighii of the skin and the 
corium. The connective tissue fibers are somewhat coarser than 
they are in the corium of the skin. Study the matrix, the pos- 
terior portion of the nail-bed. 



A LABORATORY GUIDE IN HISTOLOGY. 81 



~ 




Fig. 58. L. S. Thumb of a Fetus x30 : a, ossifying bone 
of the terminal phalanx; b, hyaline cartilage; c, blood- 
vessel; d, stratum Malpighii ; c, matrix of nail. 



Larynx, Trachea and Lung. 



Larynx. The larynx of a rabbit was fixed and hardened in 
formalin, imbedded in celloidin, and sectioned transversely. Stain 
in hematoxylin and eosin, and mount in balsam. 

Study under low power. What kind of epithelium do you 
find in the tunica mucosa? Are goblet cells 'present? Study the 
tunica or lamina propria. Are papillae present? Do you find 
any diffuse adenoid tissue? Study the tela submucosa. Look 
for mucous glands. Study the cartilages. What variety of carti- 
lage is found in the larynx? Stud)' the perichondrium. Study 
the distribution of the blood vessels. Sketch a portion as seen 
under low power naming the parts. 

Trachea. The trachea was fixed and hardened in alcohol 
and imbedded in paraffin. Fix a section to each of two slides, 



82 



A LABORATORY GUIDE IN HISTOLOGY. 




Fig. 59. Trachea: a, epithelium; b, tun- 
ica propria ; c, tela submucosa ; d, glands : 
e, perichondrium. 



remove the paraffin and stain, one in hematoxylin and eosin, and 
the other in Weigerts Fuchsfn-resorcin for about half an hour, 

wash in alcohol, treat with 
absolute alcohol, clear with 
xylol, and mount in balsam. 
The elastic fibers should be 
stained dark blue and the 
nuclei should stain but lit- 
tle if at all. 

Study under low and 
high power. The first prepa- 
ration shows the general 
structure very nicely while 
the second shows the dis- 
tribution of the elastic tis- 
sue. What is the general 
direction of the elastic fi- 
bers of the lamina propria? 
What type of glands do 
y o u find and 
where are they 
located? Make a 
sketch under low 
p o w e r, using 
both sections, so 
as to show the 
structure of the 
trachea. See Fig. 
59, Fig. 59(a). 

Lung (Pulmo). 

(a) Portions of 
the lung were 
fixed in io% for- 
malin, imbedded 
in celloidin, and 
sectioned. The 
lung of a large 
animal is best 
for studv and the 




Fig. 59(a). Mucosa and Submucosa of the Trachea: a, 
muscularis mucosae ; b, fold of mucosa ; c, duct of gland ; 
d, glands of the submucosa ; e, tip of tracheal cartilage. 



A LABORATORY GUIDE IN HISTOLOGY. 83 

portions should be kept entirely submerged in the fluid while 
undergoing fixation. Stain in hematoxylin and eosin, dehydrate, 




T. S. Medium Sized Bronchiole x80. 



clear in oil of bergamot, and mount. Study under low power 
noting the sections of bronchi, blood-vessels and the lung tissue 
which is as seen in a collapsed lung. Compare your section with 
Fig. 60 and identify the parts. Study one of the larger bron- 
chioles. What is the nature of the epithelial lining? Are goblet 
cells present? Do you find any glands in the mucosa? If so, 
what kind? What is the next tissue beneath the mucosa? Do 
you find any cartilage? Does it occur as more or less complete 
rings, or as plates somewhat irregularly disposed? Do you find 
branches of the pulmonary artery in relation to the bronchiole? 
Do you rind a branch of the bronchial artery? Sketch the bron- 
chiole and a little of the surrounding lung tissue as soon under 
low power. 

Study a small bronchiole as above. How does it differ in 
structure from a larger bronchiole? Sketch as above. Study 
Fig. 61 to learn the general relation of the blood-vessels to the 



8 4 



A LABORATORY GUIDE IX HISTOLOGY 



lung tissue and then find a respiratory bronchiole and study 
carefully. Look for the capillaries often containing blood cor- 
puscles. Study the epithelium of the air-cells. Are all of the 




Fig. 60. Lung of a Cat : a, bronchiole ; b, blood vessel ; 
c, respiratory bronchiole ; d, lung tissue. 

cells alike? How do they differ? Sketch a respiratory bron- 
chiole and a portion of the epithelium of the air-cells as seen 
under high power. 

(b) The lung of a dog was distended with a 10% solution 
of formalin after which the thorax Avas opened, the lungs re- 
moved and suspended in 10% formalin for a few days., after 
which portions were dehydrated, imbedded in celloidin, and 
sectioned. Stain and study as above noting the appearance of 
the distended lung and especially the epithelium of the air-cells. 
Sketch a portion of the lung tissue to show the epithelium and 
compare with the above. 

(c) Injected lung. The lung of a cat was injected with 
carmine-gelatin through the pulmonary artery, hardened in alco- 



A LABORATORY GUIDE IN HISTOLOGY. 



hoi, imbedded in celloidin, and sectioned. Stain in hematoxylin 
and eosin and mount. Study and make a sketch of a portion to 
show the distribution of the pulmonary artery. See Fig. 62. 




...Otttacvraf 



(d) Elastic tissue of the lung. Lung tissue was hardened 
in alcohol and imbedded in paraffin. Fix a section to the slide 
and stain as follows : Place sections for twenty-four hours in 
orcein, (1-10 gm. of orcein in 20 c. c. of 95% alcohol, and 5 c. c. 
of distilled water, to which a solution is added consisting of 

-l\\Vx\o\*,. 

-0AX-SC\O 

ov\\W suxVfci*& 
1 N ^/^ avv °^x icxc 




86 



A LABORATORY GUIDE IN HISTOLOGY. 



20 c. c. 95% alcohol, 1-10 c. c. hydrochloric acid, and 5 c. c. dis- 
tilled water), differentiate in acid-alcohol' for fifty or sixty sec- 
onds. Rinse in alcohol, and stain the nuclei with an alcoholic 
solution of methylene blue, rinse in alcohol, dehydrate in abso- 
lute alcohol, clear in xylol, and mount in balsam. Nuclei stain 
blue and elastic fibers a deep brown. Study carefully and sketch 
a portion to show the distribution of the elastic fibers. 



The Thyroid Gland (Glandula thyreoidea). 

Portions of the thyroid were fixed in formalin — Miiller's 
fluid, hardened in alcohol, imbedded in celloidin, and sectioned. 
Stain in hematoxylin and eosin. 

Another portion of the gland was fixed in Flemming's solu- 
tion and imbedded in paraffin. Fix a section to the slide, remove 
the paraffin with turpentine, and add xylol and the grades of 
alcohol down to water, and then place them in 2.5% aqueous 
solution of ammonium sulphate of iron for about five hours. 
Rinse in water and stain in the following solution of hematoxylin : 
Hematoxylin crystals, 1 gm. ; absolute alcohol 10 c. c. ; distilled 
water 90 c. c. ; diluted when used with an equal volume of dis- 
tilled water. They should be stained for twenty-four hours, 
rinsed in water, and again placed in ammonium sulphate of iron 
solution until the excess of stain is removed, after which they 
are washed carefully in distilled water, dehydrated, cleared in 

xylol, and mount- 

^AtU^wAwi, ed in balsam. This 
is known as Heid- 
enhain's Iron-he- 
matoxylin Stain. 
Study the first 
section under low 
power. Note the 
fibrous capsule in- 
vesting the gland. 
What is the shape 
of the alveoli? 
How are they 
lined? Study the 




-\>\oob-ut*%o. 






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Vv<y»V \Wto\b G\«w\o ok "Doo^Hoo. 



A LABORATORY GUIDE IN HISTOLOGY. 



colloidal substance. Does it stain uniformly and what is its 
composition? Study the second section as above, compare with 
the first, and then sketch a few alveoli to show their appearance 
under the high power. See Fig. 63. 

Huber recommends fixing with Flemming's fluid and stain- 
ing with the Ehrlich-Biondi mixture. This stain serves to dif- 
ferentiate the chief from the colloidal cells. The chief cells do 
not stain, while the colloidal cells are red with green nuclei. 
This method has given good results with us. 



The Eye (Oculus). 



Cornea. The eye of a man was removed, cleaned of super- 
fluous fat and connective tissue, placed in Flemming's solution, 
and divided into anterior and posterior halves. After fixing the 
lens was removed and one-fourth of the anterior half was stained 
in hematoxylin, dehydrated, cleared, and imbedded in paraffin. 
Fix your section to the slide, remove the paraffin with xylol, and 
mount in balsam. 

Study the cornea noting carefully the following' layers : (1) 
The corneal epithelium. How many layers of cells in it and of 
what variety are they? (2) The second layer is the anterior 
elastic membrane. What can you determine as. to its structure? 
Does it extend to the sclera? (3) The third layer is the sub- 
stantia propria or cor- 
neal ground-substance. 
Study the structure 
carefully noting that it 
seems to be composed 
of fibrous tissue, both 
in bundles and lamellae, 
between which cells or 
corneal corpuscles are 
found in the corneal 
spaces. Is the substan- 
tia propria continuous 
with the connective tis- 
sue of the sclera? (4) 
The posterior elastic Vu^AU.M 
membrane. What is its 




c 



tOYl\C<A 



,, tovweo\ ^att 






vwvscm V/Ovuta x. MSo. 



88 A LABORATORY GUIDE IN HISTOLOGY. 

structure? (5) The endothelium of the anterior chamber. 
Sketch a portion as seen under high power. See Fig. 64. 




Fig. 64(a). Section of Fetal Eye x60. 

The Sclera. Study carefully, especially near and at its junc- 
tion with the cornea. Of what layers is it composed? Study 
the canal of Schlemm. Study also the relations of the iris and 
ciliary processes as shown in the section. Sketch to show the 
general structural relations. 

The Choroid Coat (Chorioidea). Portions of the posterior 
half of the eye-ball were imbedded in paraffin, and sectioned 
transversely. Fasten to the slide, remove the paraffin, stain in 
hematoxylin and eosin. and mount in balsam. Study carefully 
under low and high power and try and distinguish the following 
layers from without inward: (1) The lamina suprachoroidea. 
What is its composition? To what layer of the sclera is it 
joined? Are pigment cells present? Do you find the perichor- 
oidal lymph-spaces? How are they formed and with what are 
they lined? (2) The lamina vasculosa. What is its structure? 



A LABORATORY GUIDE IN HISTOLOGY. 




<Aa»>*u Wui^- 



nWavw 









\W\oV i\\V*VQkAO(VOVOvCi X\00. 



How does it differ 

from the above 

in structure? 

How are the 

blood vessels dis- 
tributed? Locate 

and study the 

boundary zone. 

(3) Lamina chor- 

iocapillaris. What 

is its structure? 

Are pigment-cells 

present? (4) The 

vitreous mem- 
brane. What is its general structure? Sketch a portion to show 

these layers and their relative thicknesses and relations. See 

Fig. 65. 

Nervous Tunic. Study the preparation used above. Note 

that this coat has two layers, (1) the pigment layer and, (2) the 

t.\ \ retina. What is 

£ * \. *\ v the shape of the 

o ^ ^ cells in the pig- 

-XWuXV^Vs^^t. ment layer? What 

is the position of 
the nuclei? Study 
the relation of the 
processes of the 
cells. The section 
of the retina lies 
between the ora 
serrata and the 
macula lutea and 
the following- lay- 
ers should be dis- 
cerned and care- 
fully studied from 
without inward: 
(i) The layer oi 
visual cells which 










^ 



^*t<w\AtoAfc- 



\* 



^ 









A^VV^'vacn oWvW AW 



90 A LABORATORY GUIDE IN HISTOLOGY. 

consists of cone-visual cells and rod-visual cells. Try and dis- 
tinguish them and study their relation carefully. (2) The outer 
molecular layer. Of what elements does it consist? (3) The 
inner nuclear layer. What is its structure? (4) The inner 
molecular layer. What is its formation? (5) The layer of 
ganglion cells. What type of ganglion cell do you find? Study 
the cell processes. (6) The nerve fiber layer. Are the fibers 
medullated or non-medullated? Make a sketch showing these 
layers and their component parts. See Fig. 66. 

Retina, Teased Preparation. Carefully remove the retina 
from the eyeball and place in a 1% solution of osmic acid for 
about six hours. Wash in water and place in dilute glycerin 
until ready for use. Tease carefully on a slide in a drop of the 
glycerin, add a cover-glass and then by very gentle tapping on 
the cover-glass separate the fragments more completely. Study 
and draw under high power the various retinal fragments. The 
retinal elements ought to be very well shown by this method. 

The Crystalline Lens (Lens crystallina) . Macerate the lens 
for twenty-four hours in Ranvier's one-third alcohol, tease on a 
slide, cover and study. What is the shape of the fibers? Are 
they nucleated? How many nuclei? Sketch a few fibers as 
seen under high power. 

The Eyelid (Palpebra). The eyelid was fixed and hardened 
in alcohol, and imbedded in paraffin. Fix a section to the slide, 
remove the paraffin, stain in hematoxylin and eosin, and mount. 
Study under low and high power noting the three layers: (1) 
The cuticular layer with a very thin epidermis. Do you find 
dermal papillae? Are they of uniform size and distribution? 
What variety of glands do you find? Do you find any pigment- 
cells? (2) The middle layer. What is the structure of the tarsal 
plate? What kind of muscle do you find? Note the distribution 
of blood vessels. What kind of connective-tissue do you find? 
Has it any definite arrangement? (3) The conjunctiva. What 
kind of epithelium do you find? Are goblet-cells present? Is 
lymphoid tissue present? Is it diffuse or nodular? Do you find 
glands? Sketch a portion of the section to show the structural 
relation as seen under low power. 



A LABORATORY GUIDE IN HISTOLOGY. 



9i 



The Ear (Organon auditus). 

External Ear (Pars externa). Portions of the external ear 
were fixed and hardened in alcohol, imbedded in celloidin, and 
sectioned. Stain deeply in the elastic tissue stain and mount. 
Study under low power noting the general features of the sec- 
tion. The skin is rather thin in the external ear. Do you find 
hair-follicles? Do you find sebaceous glands? Are the sweat- 
glands present on both surfaces? What kind of cartilage do you 
find? Are the elastic fibers uniformly distributed? Sketch under 
low power to show the general structural features. 







^4 _^<*\<x \> t &^v\\ . 



;u\ 









^^. . *\t*v>C-\^v «,. 



Inner Ear (Pars interna). The cochlea of a guinea-pig was 
fixed for twelve hours in Flemming's solution, and after washing. 
was decalcified in 2% hydrochloric acid (2% nitric acid, or 1% 
chromic acid would do), imbedded in celloidin, sectioned parallel 
to the longer axis of the section, and stored in 8o r < alcohol. Stain 
in hematoxylin and eosin, and mount in balsam. 



9 2 



A LABORATORY GUIDE IN HISTOLOGY. 



Study the section carefully under low power. Do you find 
the axis of the cochlear canal? Do you find the lamina spiralis 
ossea which separates the canal into the scala vestibuli and the 
scala tympani? How are these portions of the canal lined? Can 
you find the cochlear duct? If so try and find the organ of 
Corti and identify and study its parts. The pillars of Corti form 
a sort of arch. Do you find the hair-cells? Look for the lamina 
reticularis and the membrana tectoria. Try and find the cells 
of Deiter and those of Hensen. Sketch as seen under low power 
and identify and label all of the parts by comparing with the 
cuts or with the aid of the instructor. See Fig. 67. 

Fetal Ear. Stain the sections of human fetal ear in hema- 
toxylin and eosin, and mount. Study carefully and compare with 
the section given above; Sketch and label the important parts. 



The Olfactory Mucous Membrane. 

Isolated Epithelium. Portions of the mucous membrane of 
a dog's nose were macerated in Ranvier's one-third alcohol for 
two hours and were then placed in a 1% solution of osmic acid 
for twenty minutes. Tease carefully on a slide and examine. 
Stain another portion with methylene blue., wash, tease, and 
mount in Farrant's gum glycerin. 

Study under high power. What forms of epithelial cells do 

you find? How can 
you distinguish be- 
tween the olfactory 
cells and the susten- 
tacular cells? Sketch 
and label as seen un- 
der high power. 

Epithelium in Sec- 
tion. Portions of the 
olfactory mucous 
membrane were fixed 
and hardened in al- 
cohol, imbedded in 
celloidin, and sec- 
tioned. Stain in he- 










A LABORATORY GUIDE IN HISTOLOGY. 



93 



matoxylin and eosin, clear, and mount. Study the epithelium, 
carefully noting its structure. Do you find a basement mem- 
brane? Do you find glands? Are they of the serous or mucous 
type? How are the blood vessels distributed? Sketch to show 
the most important structures. See Fig. 68. 



Nerve Histology. 

Nerve Cells. With a scalpel remove a small portion of the 
gray matter from the anterior horn of the spinal cord of the ox, 
place it between two clean cover-glasses and make a cover-glass 
preparation or smear. Allow the smear to dry in the air and 
then place it in cover-glass forceps and pass quickly two or three 
times through the flame of a Bunsen burner. Stain for twenty 







v wk\. vWut-ct\\«, S^\xvo\C/ovk sk 0*. 



or thirty minutes in a i% aqueous solution of methylene blue. 
Wash in water, dry thoroughly between pieces of filter paper, 
or in the air, and mount in balsam. 

Study the preparation under low and then under high power. 
Note the general form of the cell-body. Are the cells unipolar, 
bipolar, or multipolar? Do you find a neuraxis? Are the cells 
alike as to form and size? Is the protoplasm clear or granular? 
Can you see any fibrillation in the protoplasm under the high 
power? Are nucleoli present? Can you find the implantation 
zone? Make drawings. See Fig. 69. 



94 A LABORATORY GUIDE IN HISTOLOGY. 

Nerve Cells Macerated. Macerate portions of the gray mat- 
ter from the anterior horns of the spinal cord for a week or ten 
days in 1-3 alcohol, a 1% solution of potassium dichromate, or a 
5% solution of chromic acid. Thionin is a good stain to use after 
alcohol as a fixative. Lithium carmine after chromic acid is 
recommended by Huber. The stained material should be care- 
fully teased and examined in glycerin, or it may be mounted in 
gum glycerin. Study and note the structure and form as above. 
You should be able to trace portions of the neuraxes. Sketch a 
cell showing the neuraxis. 

Nerve Cells of the Cerebral Cortex. Small pieces of the cere- 
bral cortex of a cat were placed in the following mixture, as 
recommended by Fish : 

Formalin 2 c. c. 

Potassium dichromate, 3%, 100 c. c. 

for three days, using fifty times their volume of fluid, and kept 
in the dark. The tissue was then placed in the 3% potassium 
dichromate solution for three or four days. The potassium di- 
chromate was replaced by a ^2% solution of silver nitrate until 
the chromate of silver was no longer precipitated. A fresh solu- 
tion of silver nitrate was poured over the tissue and it was kept 
in the dark for from three to five days. It is best to change the 
silver nitrate solution after ten to twelve hours. The tissue was 
then imbedded in celloidin as follows : Dehydrate in 95% alcohol, 
15-20 minutes. Change the alcohol once or twice and agitate. 
Absolute alcohol for 30-40 minutes. Ether-alcohol, 20 minutes. 
Ether, 15 minutes. Thin celloidin, 30 minutes. Thick celloidin, 
15 minutes. Tissue was mounted on blocks and placed in 
chloroform for 10 minutes, after which it was placed in a modi- 
fied Eycleshymer s clearing fluid (phenol, 25 parts ; oil of 
cedar, 50 parts; and oil of bergamot, 50 parts), for one hour. 
The tissue may remain in oil a day or two without seeming to 
suffer much injury. Sections were cut with a sliding microtome, 
using the clearing fluid to wet the tissue and the knife, and trans- 
ferred to a dish of clearing oil. Take a section from the clearing 
oil and place it on a clean slide, press down and blot with a piece 
of filter paper, and cover with a large drop of very thick Canada 



A LABORATORY GUIDE IN HISTOLOGY. 



95 



\i 



hw 



\ 






balsam. Do not use a cover-glass and dry quickly in a warm, 
dry place protected from dust. 

Study the section with low power. The plexus of blood 
vessels may confuse you but search for pyramidal cells, stained 
a brownish-black, with a 
single neuraxis extending 
from the base of the cell- 
body into the white mat- 
ter, and branching den- 
dritic processes extending 
toward the surface of the 
cortex. Only portions can 
be found in connection 
with a single cell. Note 
the size of the dendrites 

as compared with the V\^. r lo.lu^o k m\^o\C%\\«, ol & C*\. feoWv. 
neuraxis. Do the cells ^ 

have a definite arrangement? Could they be said to have a 
characteristic form? Do they have more than one dendrite? 
Note the branching of the dendrite. Sketch several pyramidal 
cells and label the parts. See Fig. 70. 









.\><x%o\ o<ot«,i,s 



Nerves. 

Fresh Fibers. Carefully remove the sciatic nerve from a 
frog and place it in physiological normal salt solution (.6%). 
With very sharp scissors remove a piece about one-half inch 
in length and place it on a slide and tease carefully keeping the 
fibers as nearly straight as possible ; cover with a cover-glass 
and examine first with low power, and then with the high power. 
Use a small diaphragm opening for the high power. 

Search for the neuraxis or axis cylinder seen as a light band 
running down through the center of the fiber. Outside of the 
neuraxis is the myelin sheath which has a glistening appearance 
with a slightly greenish tint. Do you find the nodes of Ranvier? 
Estimate the length of the internodal segments. Look for the 
neurilemma as it crosses from one internode to another. Is the 
medullary sheath continuous from internode to internode? Do 
you find the nuclei of the internodal segments? Look for the 



9 6 



A LABORATORY GUIDE IN HISTOLOGY. 



segments of Lantermann. Do you find the long, oval neurilem- 
ma nuclei? Note the contraction ring of the neurilemma at the 
nodes. Are all the fibers of uniform diameter? Do they branch? 
Make a sketch to show as many of these points as possible. 

Stained Nerve Fibers. The sciatic nerve of a frog, or a 
small nerve of a mammal, was placed in a .5% solution of osmic 

acid for twenty-four hours, 
washed in water, and stored in 
70% alcohol. Take the portion 
given you and tease carefully 
on a slide in dilute glycerin, 
cover and examine, first with 
the low and then with high 
power. The medullary sheath 
is stained a deep black. Why? 
Can you trace a neuraxis ? Study 
the nodes and neurilemma con- 
traction ring. Do you find the 
segments of Lantermann ? 
Sketch a node of Ranvier with 
portions of the internodal seg- 
ments as seen under high pow- 
er. See Fig. 71. 







'W 



Stained Nerve. A section 
of human ulnar nerve was 
hardened in formalin, imbedded in paraffin, and sectioned longi- 
tudinally. Fasten to a slide with albumin fixative and stain in 
hematoxylin, Bcehmer's is best. Study under high power. What 
is the appearance of the medullary sheath? Are the internodal 
nuclei visible? The neuraxis usually stains deeply. Sketch a 
portion of the section. 

Stained Nerve. A cross section of the same nerve was hard- 
ened in Miiller's fluid, imbedded in celloidin, and sectioned. Stain 
in aniline blue and safranin, dehydrate, clear in oil of bergamot, 
and mount in balsam. Study under low power noting the epi- 
neurium and the perineurium. The neuraxes are stained blue, 
the nuclei red, and medullary sheaths a reddish-yellow. Sketch 



A LABORATORY GUIDE IN HISTOLOGY. 97 



Q\\lW\\\XK*\. 




VV&IA*\\AW\. 



. Wt\x\ c\\w 
-^y\v\c\\x\uvy\. 



\ \ 0^ lA . O. J\WW0*\j v\\w C\\' \\tx \) I. 



2l portion carefully, labeling all of the parts. See Figs. 72 
and 72(a). 




Fig. 72(a). T. S. of Peripheral Nerve x60. 

Non-medullated Nerves, (a) The splanchnic nerves of a 
dog were fixed in formalin, and stained in hematoxylin. Tease 



A LABORATORY GUIDE IN HISTOLOGY. 



carefully in glycerin and study under high power. Are the fibers 
medullated or non-medullated? Do the non-medullated fibers 
possess nodes of Ranvier? Do they have a primitive sheath or 
neurilemma? Do you find nuclei? Sketch a typical non-medul- 
lated fiber. See Fig. 71. 

(b) Pieces of the vagus nerve were treated with a .5-1% 
solution of osmic acid for twenty-four hours and they are to be 
carefully teased and examined in dilute glycerin. Between the 
medullated fibers the non-medullated are found. Compare with 
(a) above and sketch a few fibers. 

Ganglia. Cross sections of the spinal cord of a cat were 
made so as to pass through the posterior root ganglia. Stain 
deeply in Ehrlich's acid-hematoxylin and Van Gieson's stain. 







V va.^, T\\&cwa*\\ 



Dehydrate, clear in Eycleshymer's nerve mixture, and mount in 
balsam. Study under low power. Note the capsule of the gang- 
lion and its septse or trabeculae. How are the ganglion cells 
arranged? Study the cells under high power. Are they uni- 
polar or bipolar? Note the large nucleus and the nucleolus. 
What is the relation of the cells to each other? Do you find any 
fibers? Do any fibers end in the ganglion? Sketch under low 
power to show general relation and arrangement, and under the 
high power to show as much as you can of the ganglion cell 
and its structure. See Fig. 73. 



A LABORATORY GUIDE IN HISTOLOGY. 



99 



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Spinal Ganglion Cells Macerated. Place pieces of a spinal 
ganglion in i% osmic acid for five hours. Replace the acid with 
water containing a crystal of thymol to prevent mold formation 
and allow the tissue to macerate for three or four days. Tease 
fragments of the tissue on a slide in a drop of 50% glycerin, 
cover and study. The ganglion cells are large, spheroidal, with 
large nuclei. Do you find cells having the nucleated connective 
tissue sheath? Are the cells unipolar or bipolar? Do the nuc- 
leoli show clearly? Note the junction of the nerve fibers with 
the cell process. Fat cells are often present in the connective 
tissue and they take a very deep black stain in the osmic acid. 
Make sketches of several cells so as to show the structure. 

Nerve Endings. Treat pieces of the ocular or intercostal 
muscle, other small muscles would do as well, by Ranvier's 
lemon-juice meth- 
od as follows : The 
lemon - juice 
should be filtered 
through clean new 
flannel, after 
which pieces of 
the tissue are 
placed in it until 

they become XW^.X^&c* Wtx»t-«.yvV\vv^Vv^%^\<\^t. 

transparent, usu- 
ally requiring five or ten minutes, after which they are to be 
quickly rinsed in distilled water and placed in the dark in a 1% 
solution of gold chloride for twenty or twenty-five minutes, after 
which they are to be washed in water and placed in distilled 
water to which acetic acid has been added in the proportion of 
one drop of acid to each 25 c. c. of water. Now expose to the 
light for at least twenty-four hours. The reduction of gold is 
not very complete and such material is only suited for present 
study. Permanent preparations may be made by placing the 
tissue in formic acid of 25% strength. The reduction is usually 
complete in twenty-four hours. 

Tease the tissue carefully on a slide and search for the 
motor-endings. Study carefully and make several sketches to 
show typical forms of endings. See Fig. 74. 







ioo A LABORATORY GUIDE IN HISTOLOGY. 

Pacinian Corpuscles. The mesentery of a cat furnishes suit- 
able material for this study. These bodies are readily seen in 
the mesentery and they should be very carefully removed and 
freed from fat. Mount in a drop of normal saline. A coarse 
hair or a fragment of a cover-glass should be placed beside the 
corpuscle before covering with a cover-glass to prevent crushing. 
Study and sketch under low and high power. What is the shape 
of the corpuscle? Of what are the tunics composed? Where 
does the nerve enter the corpuscle? Does the nerve retain its 
sheath? How does it terminate within the corpuscle? Search 
+ 'or the epithelioid cells between the tunics, and distinguish 
sharply between these cells and the tunics. 

Crosses of Ranvier. — Silver Nitrate Method. Place portions 
of a small nerve, or spinal nerve roots, in a 1% solution of silver 
nitrate. Keep it in the dark for about twenty-four hours. Re- 
move from the silver solution, rinse quickly in distilled water 
and place on a slide in a drop of glycerin and carefully tease 
one end of the fiber, cover, and expose to the sunlight for twenty- 
five or thirty minutes. 

Study under high power. Do you find the crosses? Why 
are crosses formed at the nodes? Do you find the transverse 
striations known as Frommann's lines? Sketch. 

Spinal Cord (Medulla spinalis). 

(a) A portion of spinal cord from the cervical region was 
hardened in corrosive sublimate in normal salt solution, or in 
formalin. After further treatment with iodized alcohol and pure 
alcohol, in case the sublimate be used., the tissue was imbedded 
in celloidin. and sectioned. You will stain the section on a slide 
in borax-carmine., dehydrate, clear in Eycleshymer's mixture. 
and mount in balsam. 

Studv under the low power and note the form of the cord, 
fissures., membranes and nerve-roots. Examine the gray matter. 
noting the relative size and position of the anterior and posterior 
cornu. Do you find any definite regions or cell areas in the gray 
matter? Name them by consulting the figure. Examine the 
white matter more carefully, trying to see if it is divided into 



A LABORATORY GUIDE IN HISTOLOGY. 



IOI 



definite areas. Sketch the cross-section under the low power 
being careful to preserve the proper proportions and to keep the 
relative size of the various parts. See Fig. 75. Compare with 
this section sections similarly prepared taken from the dorsal 
and lumbar segments of the cord. Note carefully the differences 
in the characteristics of the cord at the various levels. Interpret 
your findings. Make sketches to show chief structural charac- 
teristics at the different levels of the cord. 




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(b) A section of the spinal cord of an ox was hardened in 
fluid consisting of 3% potassium bichromate, 98 parts, and for- 
malin, 2 parts. The tissue was imbedded in celloidin and sec- 
tioned. Stain the section you receive in Weigert's hematoxylin, 
wash, dehydrate, clear, a phenol-xylol mixture is good, or in 
Eycleshymer's nerve fluid, mount in balsam, and study as above. 
noting the finer details in the structure under the high power. Do 
not attempt to make a complete sketch but till in portions of 
both gray and white matter in a complete outline sketch oi the 
cord. 

(c) This portion was stained by the rapid Golgi method 
(mentioned on page 94), imbedded in celloidin. and sectioned. 



102 A LABORATORY GUIDE IN HISTOLOGY. 

Remove the excess of clearing oil and mount in very thick bal- 
sam, without a cover-glass. Study under low power and make 
drawings of typical cells and structures. 

(d) Spinal Cord Stained in Nigrosin and Eosin. Stain the 
section for one hour in a i% aqueous solution of nigrosin. Wash 
in distilled water for five minutes. Stain for five minutes in a 
i% solution of eosin. Wash in 70% alcohol for several minutes 
and place in 95% alcohol until stain ceases to be given off. Clear 
in oil of bergamot for ten to fifteen minutes, and mount in bal- 
sam. Study as above. 

(e) Cells of Spinal Cord Macerated. Macerate portions of 
the gray matter from the spinal cord for three or four days in 
a test tube of Ranvier's one-third alcohol. Shake portions of 
the macerated tissue in a test tube one-half full of water so as 
to separate it into finer fragments. After the fragments settle 
pipette off the water and add a dilute solution of picro-carmine. 
After staining sufficiently, remove some of the tissue with a 
pipette and examine on a slide without a cover-glass under low 
power. If cells are sufficiently separated and stained add a 
cover-glass. (To prevent crushing the cells place a hair or a 
fragment of a very thin cover-glass beneath the cover-glass.) 
What types of cells do you find as to form? Study the axones. 
Do you find neuro-fibrils? Do you find pigment? Is the pigment 
uniformly distributed? Make sketches of the various forms of 
neurones present. If you wish to preserve this specimen mount 
in 50% glycerin and seal the cover-glass with cement or balsam. 
Study carefully. 

Spinal Bulb (Medulla oblongata). The spinal bulb was fixed 
and hardened in formalin-alcohol, imbedded in celloidin and sec- 
tioned. You will, receive sections passing through the motor 
and sensory decussations, just above the decussations, and 
through the olive. Stain the sections somewhat deeply in Ehr- 
lich's acid-hematoxylin, wash in water, and stain for from one 
to three minutes in Van Gieson's stain. Dehydrate, clear in 
Eycleshymer's nerve mixture, and mount in balsam. Study 
carefully under low power. Bearing in mind the structure of 
the cervical part of the spinal cord, study the changes produced 
by the decussation. What fiber tracts no longer appear in the 



A LABORATORY GUIDE IN HISTOLOGY. 103 

lateral area? What tracts find their terminations in the spinal 
bulb? What fiber tracts take origin from the nuclei of the bulb? 
Compare gray matter of the bulb with that of the cord. Make 
drawings to show general structure. 

Pons. The pons of a dog was fixed in formalin-Muller's 
fluid, hardened in alcohol, imbedded in celloidin and sectioned 
transversely. Stain deeply in Bhrlich's acid hematoxylin, wash 
and stain for two minutes in Van Gieson's stain. Dehydrate in 
picric-alcohol. Clear in Eycleshymer's mixture, and mount in 
balsam. Study under low power noting the general structure. 
What fiber tracts do you find that are not found in the spinal 
bulb? What tracts found at lower levels are present? Do they 
have the same relative position as in the bulb? How many 
longitudinal strands are found? What and where are the nuclei 
of the pons? Study carefully and make a drawing to show the 
general structure. 

Prepare sections as above from the lower and upper parts 
of the pons. 

Mesencephalon. Portions were fixed as above.. Stain sec- 
tions as for pons above. Study under low power. What fiber 
tracts are present? What nuclei do you find? (You will receive 
sections for staining from the mesencephalon at different levels. 
Compare them and study them in their proper relations to each 
other.) What cranial nerves have their nuclei of origin in the 
mesencephalon? Locate each nucleus, and make a drawing 
showing the relative position and relations of fiber tracts and 
nuclei. 



The Cerebellum. 

Harden small pieces of the cerebellum in bichloride of mercury 
or formalin (formalin of 10% strength, with prolonged staining 
in hematoxylin gives fair results for the general features), com- 
plete the hardening and dehydration in alcohol, and imbed in 
celloidin. Cut sections at right angles to the cerebellar folds and 
stain in hematoxylin, Delafield's is probably best, dehydrate. 
clear, and mount in balsam. 



104 A LABORATORY GUIDE IN HISTOLOGY. 



Study the general structure and relations under low power. 
Study the gray cortex under high power noting these layers and 
compare with the Golgi cortex, (i) An outer molecular layer. 
What kind of cells do you find, large or small ganglion cells? 
What tissue seems to form the greater part of this layer? (2) 
Cell layer of Purkinje's cells. Can you trace an axon from the 
base of the cell-body? How many dendritic processes at the 
opposite pole? How do they branch? Do the branches seem 
to have varicose enlargements? Do they anastomose? Do you 
find basket cells? (3) Granular layer containing small granular 







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ganglion cells and large stellate cells. How many dendrites 
do the small cells have and how do they end? Can you trace 
the neuraxes toward and into the molecular layer? Look for 
the large stellate cells close to the molecular layer, noting the 
branching and course of the dendrites and neuraxes. Sketch a 
portion showing as much as you can of the cortical layers. See 
Fig. 7 6. 

Golgi Method. Portions of the cerebellar cortex were treated 
by the rapid Golgi method mentioned on page 94. Mount as 
there described and study and compare with the above. Sketch 



A LABORATORY GUIDE IN HISTOLOGY. 105 




Fig. 77. Cells of Purkinje of Dog x60. Parts of dendritic branching are 
not shown because they lie in different planes. 

as seen under low power, and sketch several cells of Purkinje 
as seen under high power. See Fig. JJ. 

The Cerebrum. 

Stained Cortex. Small pieces of the cerebral cortex were 
fixed in bichloride of mercury, hardened in alcohol, imbedded in 
celloidin, and sectioned. Stain in hematoxylin, and, very lightly, 
in eosin, dehydrate, clear, and mount in balsam. This section 
is useful for the purpose of showing general layers. What kind 
of tissue composes the larger portion of the molecular layer? 
Do you find any nerve cells? Look for a thin stratum of small 
medullated fibers just beneath the pia mater. Is the molecular 
layer sharply marked off from the layer beneath it? Describe 
the structure of the granular layer. Note the relative number 
of cells in the granular and molecular layers. 

Golgi Cortex. Pieces o\ the cerebral cortex were prepared 



io6 A LABORATORY GUIDE IN HISTOLOGY. 






by the rapid Golgi method described on page 94, imbedded in 
celloidin, and sectioned. Remove the excess of clearing fluid 
and mount in a drop of very thick balsam, without using a cover- 
glass. Study under low power, noting carefully the relative 
number of cells in each layer. How are the cells distributed in 
^ v v v the outer layer? Do they 

pAoWW\^. possess typical forms ? 
Do you find distinct boun- 
daries between the layers? 
Note the relative size of 
the cells of the pyramidal 
layers. From what por- 
tion of the cell body is 
the axon given off? How 
many dendrites, and 
where do they terminate? 
What forms of cells do 
^\w*\ov^W**c&\v you find in the layer be- 
neath the layer of large 
pyramidal cells? Make a 
sketch showing the struc- 
ture of the cortex. See 
Fig. 78. 

Nerve Fibers of the 







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V, 



Cortex. A portion of the cerebral cortex of a dog was fixed in 
Midler's fluid, hardened in alcohol, imbedded in celloidin and 
sectioned. Stain the sections in Weigert's hematoxylin, dehy- 
drate, clear, phenol-xylol is best for clearing, and mount. The 
nerve fibers are stained a blue-black color. Note carefully the 
distribution of nerve-fibers in the cortex. Sketch a portion of 
the cortex, using the low power. 

Hypophysis cerebri (Pituitary body). The hypophysis was 
removed and fixed in 95% alcohol, to which a few c. c. of forma- 
lin was added, imbedded in celloidin and sectioned. Stain in 
acid-hematoxylin and Van Gieson's stains, dehydrate, clear, and 
mount in balsam. Study carefully under low and high powers. 
Note that it consists of two lobes, one anterior and one posterior. 
The anterior developed as a protrusion of the oral epithelium. 
Note that it consists of tubules, lined with epithelium, and held 



A LABORATORY GUIDE IN HISTOLOGY. 107 

together by connective tissue. Do you find any ciliated epithe- 
lium? Do any tubules contain a colloid-like material? Are the 
cells clear or granular? Some of the tubules will show no 
lumen, but a solid mass of cells. Study the blood vessels. Do 
you find sinusoids among them? Note that the posterior lobe 
consists mainly of neuroglia and vascular connective tissue. 
This lobe developed from the infundibulum connected with the 
third ventricle. Do you find any small masses of cells that re- 
semble epithelial cells of the anterior lobe? Do you find any 
nerve cells or fibers? How is the anterior lobe separated from 
the posterior lobe? Make a sketch under low power to show 
general structure. 

Formulae for Reagents. 
A. Stains. 

(1) Bcehmer's Hematoxylin. 

Hematoxylin crystals, 1 gram. 
Absolute alcohol, 10 c. c. 
Potassium alum, 10 grams. 
Distilled water, 200 c. c. 

Dissolve the alum in the water and the hematoxylin in the 
alcohol. Mix while stirring constantly. Place in an open jar. 
protect from dust, and let ripen for two or three weeks. Filter, 
and the stain is ready to use. 

(2) Delafield's Hematoxylin. 

Hematoxylin crystals, 4 grams. 

Absolute alcohol, 25 c. c. 

Sat. aq. solution of ammonia alum, 400 c. c. 

95% alcohol, 100 c. c. 

Glycerin, 100 c. c. 

Dissolve the hematoxylin in the absolute alcohol and add 
to the solution of alum. Place in an open dish and expose to the 
light for four or five days and filter. Add the 95% alcohol and 
the glycerin and let the solution ripen for six or eight weeks. 
It is now ready for use after filtering. It is diluted with dis- 
tilled water before using. 



108 A LABORATORY GUIDE IN HISTOLOGY. 

(3) Ehrlich's Acid Hematoxylin. 

Hematoxylin crystals, 2 grams. 
Absolute alcohol, 100 c. c. 
Glacial acetic acid, 10 c. c. 
Glycerin, 100 c. c. 
Distilled water, 100 c. c. 
Potassium alum, in excess. 

This stain should ripen in the light for some time until it 
acquires a deep-red color. It stains and keeps well for years 
if kept in well-stoppered bottles. 

(4) Aqueous Solution of Borax-Carmine. 

Grind 2 grams of carmine with 8 grams of borax in a mortar, 
and add to it 150 c. c. of distilled water. Let it stand for from 
twenty-four to thirty-six hours and filter when it is ready for use. 

(5) Safranin. 

Safranin, 1 gram. 
Aniline water, 90 c. c. 
Absolute alcohol, 10 c. c. 

Prepare the aniline oil by shaking 8 to 10 c. c. of aniline oil 
in 100 c. c. of distilled water, and filtering through a wet filter. 
Dissolve the safranin in the aniline water and then add the 
alcohol. It must be filtered before using. Does not keep well. 

(6) Weigert's Hematoxylin. 

Hematoxylin crystals, 1 gram. 
Absolute alcohol, 10 c. c. 
Lithium carbonate, 1.2 grams. 
Distilled water, 100 c. c. 

Dissolve the hematoxylin crystals in the alcohol, the lithium 
carbonate in the water, and mix the two solutions. 

(7) Congo Red. 

Make a .5-1% aqueous solution. It is particularly useful in 
staining the parietal cells of the fundus of -the stomach since they 
seem to have a special affinity for the acid. It is also used as a 
stain for the axis-cylinder of a nerve fiber. 



A LABORATORY GUIDE IN HISTOLOGY. 109 

(8) Thionin. 

A concentrated aqueous solution is usually used. It stains 
chromatin readily, and stains plasmatic elements if the staining 
process be prolonged. It is more used as a specific mucin stain. 

(9) Orcein, Israel's Formula. 

Orcein, 2 grams. 

Glacial acetic acid, 2 c. c. 

Distilled water, 100 c. c. 
This gives a blue stain in the nucleus and a red stain in the 
cytoplasm. After staining wash the section in distilled water, 
dehydrate rapidly, passing through absolute alcohol to thick 
cedar oil in which it is mounted. 

(10) Van Gieson's Stain. 

(a) Make a saturated aqueous solution of acid fuchsin. 

(b) Make a saturated aqueous solution of picric acid. 
Add (b) to (a) until the mixture is garnet red. 

(11) Elastic Tissue Stain of Harris. 

Hematoxylin, 0.2 gram. 
Aluminium chloride, 0.1 gram. 
50% alcohol, 100 c. c. 
See page 25. 

(12) Acid Fuchsin. 

Use a 0.5-1% aqueous solution. 

(13) The Ehrlich-Biondi Mixture. 

Take 200 c. c. of a saturated aqueous solution of orange G 
and add to it while stirring 40 c. c. of a saturated aqueous solu- 
tion of acid fuchsin, and too c. c. of a saturated aqueous solution 
of methyl green. The saturated solutions should be prepared 
several days before using and they must be completely saturated. 
Sections should be stained for from twelve to twenty-four hours, 
dehydrated, cleared with xylol, and mounted in xylol-balsam. 

(14) Heidenhain's Iron-Hematoxylin Stain. 
Hematoxylin crystals, 1 gram. 

Absolute alcohol, 10 c. c. 
Distilled water, 90 C. c. 



no A LABORATORY GUIDE IN HISTOLOGY. 

To be diluted with an equal volume of distilled water when 
used. A mordant of a 2.5% solution of ammonium sulphate of 
iron is used for five or six hours. After staining for twenty-four 
hours in the hematoxylin the ammonium sulphate of iron solu- 
tion is used to remove the excess of the stain. While treating 
the tissue with the ammonium sulphate of iron, examine sections 
with the microscope so that you may know when the tissue is 
sufficiently destained. Wash thoroughly in water, dehydrate, 
etc. This stain is useful for mitosis, especially in plant tissue, 
and for the testis. 

(15) Eosin. 

Eosin is commonly used as a 2% solution in 60% alcohol, 
though saturated aqueous solutions may be used as well as sat- 
urated alcoholic solutions. 

B. Macerating Fluids. 

(1) Ranvier's One-third Alcohol. 

Fresh tissue should be macerated from eighteen to twenty- 
four hours, after which it may be teased on a slide in a drop of 
dilute glycerin. Or, after macerating, treat for several hours in 
a 5% solution of osmic acid before teasing. 

(2) Hydrochloric Acid. 

Hydrochloric acid in a 25-30% solution is commonly used to 
macerate kidney tissue. It should act at least twelve hours after 
which the tissue is washed and teased in water or dilute glycerin. 
Instead of teasing the tissue may be dissociated by vigorous 
shaking in a test tube. 

(3) Caustic Potash. 

A 30% aqueous solution is much used for macerating cardiac 
and smooth muscle. It should act for about twenty minutes 
after which the tissue is placed in a saturated aqueous solution 
of potassium acetate to which a little glacial acetic acid has been 
added in the. proportion of about one drop of acid to 5 c. c. of the 
acetate solution. After twenty-five minutes the tissue may be 
teased and examined. 



A LABORATORY GUIDE IN HISTOLOGY. in 

(4) Nitric Acid. 

It may be used in a 30% solution, or in a 20% solution of 
fuming nitric acid. 

(5) Chromic Acid. 

This is used in aqueous solutions of from 0.2-1% strength. 
It is used to macerate smooth muscle, and may be used for nerve 
tissues. 



C. Fixing Fluids. 

(1) Bichloride of Mercury. 

A saturated solution in distilled water is used. A saturated 
solution in physiological normal salt solution (.6%) makes a 
good fixing agent. 

Huber combines it with formalin. This seems to be useful 
in embryonic tissue, especially developing bone. He adds four 
parts of formalin to one hundred parts of a saturated aqueous 
solution of bichloride of mercury. After fixing the tissues are 
washed and treated with iodized alcohol to remove the crystals 
of sublimate. Add iodin to the 80% alcohol until it does not 
become decolorized longer, then dehydrate and imbed, or store 
in 80% alcohol until needed. 

(2) Miiller's Fluid. 

Bichromate of potassium, 2.5 grams. 
Sulphate of sodium, 1 gram. 
Distilled water, 100 c. c. 

This solution is much used for nerve tissues and for large 
pieces of tissue. One objection to its use is that it acts very 
slowly, and hence it should not be used if the finer details of cell 
structure are desired, as post mortem changes usually occur to 
some extent before the killing and fixing process begins. Fix 
for several weeks. Wash for twenty-four hours, dehydrate and 
imbed. Fixing fluid should be changed every day or so and kept 
in the dark while fixation is going on. 



ii2 A LABORATORY GUIDE IN HISTOLOGY. 

(3) Flemming's Solution. 

2% aqueous solution of osmic acid, 4 c. c. 
1% aqueous solution of chromic acid, 15 c. c. 
Glacial acetic acid, 1 c. c. 

It is best to keep the osmic acid and chromic acid in separate 
bottles and combine them and add the acetic acid when wanted 
for use. Fix for twenty-four hours or longer. Wash in running 
water for twenty-four hours. Dehydrate with graded alcohols. 

(4) Carnoy's Fluid. 

2 or 3% aqueous solution of chromic acid, 45 c. c. 
2% aqueous solution of osmic acid, 16 c. c. 
Glacial acetic acid, 3 c. c. 

Fix for one hour and treat with absolute alcohol and imbed. 

(5) Alcohol. 

Small pieces of tissue may be placed in absolute alcohol, 
being killed, fixed, hardened, and dehydrated at the same time. 
Unless absolute alcohol is used, 35% alcohol should be used for 
a few hours, followed by 50%, 70% 85%, etc., as tissue placed 
directly in 95% alcohol suffers considerable shrinkage. 

(6) Formalin. 

Formalin in a 5-10% solution is much used, especially for 
nerve tissues. It is not best to use it in case white fibrous con- 
nective tissue predominates in the section as it hardens it very 
greatly. Nor is it a good fixing agent for portions of such tissues 
as the stomach as it does not harden the tissue uniformly and it 
does not cut well. 

(7) Formalin— Miiller's Fluid. 

Miiller's fluid, 100 c. c. 
Formalin, 10 c. c. 

Add the formalin to the Miiller's fluid just previous to use. 
Fix the tissues in this fluid for from twenty-four to seventy-two 
hours, and wash for twenty-four hours in running water. After 
washing store in 80% alcohol until needed. 



A LABORATORY GUIDE IN HISTOLOGY. 113 

(8) Hatai's Fluids for Fixing Spinal Ganglion Cells. 

1. Bichloride of mercury, sat. sol. in formalin, 6 c. c. 
Glacial acetic acid, 10 c. c. 

Physiological normal saline, 3 c. c. 

2. Picric acid, sat. sol. in 10% formalin, 3 c. c. 
Glacial acetic acid, 1 c. c. 

Bichloride of mercury, 1 gram. 

The tissue should be fixed in either of these fluids for the 
same length of time, for seven to twelve hours. After fixing, 
wash in running water five or six hours. Wash in 35% alcohol, 
dehydrate, and imbed by the usual methods. Methylene blue 
and toluidin blue give the best results as stains where either of 
these fluids are used as a fixative. 



Mayer's Albumin Fixative. 

This is made by taking equal parts of white of Qgg and 
glycerin and adding to it a little salicylate of soda or gum cam- 
phor to prevent decomposition. 

Acid Alcohol. 

Add to 50% or 60% alcohol about 2% of hydrochloric acid. 

Graded Alcohols. 

To prepare alcohols of a lower grade from 95% ethyl alco- 
hol, take as many parts of the 95% alcohol as the strength 
wanted, and add the difference between 95 and the required 
strength of distilled water. For example, if 80% alcohol is de- 
sired, take 80 c. c. of the 95% alcohol and 15 c. c, the difference 
between 95 and 80, of distilled water. This is sufficiently ac- 
curate for all practical purposes. Where special bottles are used 
for the graded alcohols, measure the bottles and with a tile make 
marks at the level of the alcohol and that of the mixture. Then 
it is only necessary to fill bottle with 95% alcohol up to first 
mark and fill with water to the second mark, thus making meas- 
uring unnecessary each time the alcohol is prepared. 



ii4 A LABORATORY GUIDE IN HISTOLOGY. 

Ammonia Alum. 

For use in removing the excess of hematoxylin after over- 
staining take a 2-3% aqueous solution of ammonia alum. 

Lugol's Solution. 

Distilled water, 100 c. c. 
Potassium iodide, 6 grams. 
Iodin, 4 grams. 

Carmine-gelatin Injection Mass. (Ranvier). 

Soak fifty grams of Paris gelatin in water for thirty minutes, 
or until it becomes soft, and then melt it in the water it has 
absorbed in a porcelain vessel over a water-bath. When it is 
completely melted add a solution of five grams of carmine in just 
enough ammonium hydrate to effect the solution of the carmine 
forming a transparent solution. Stir the mixture constantly 
keeping it warm over the water-bath. The excess of ammonia 
must be neutralized. Add drop by drop, while stirring, a solu- 
tion of one part of glacial acetic acid to three parts water. When 
you are near the point of neutrality dilute the acid still further. 
The odor gradually changes from the ammoniacal to the sour 
odor of the acid. This neutralization must be effected slowly and 
carefully as a single drop of acid in excess may spoil the mixture. 
Filter through clean flannel. 

Farrant's Gum-glycerin. 

Glycerin, 50 c. c. 
Distilled water, 50 c. c. 
Pure gum-arabic, 50 grams. 
Arsenious acid, 1 gram. 

Dissolve the acid in water. Mix with the gum-arabic in a 
mortar. Add the glycerin and filter through fine new muslin. 

Stock or Thick Solution of Celloidin. 

Dissolve 12 grams Schering's celloidin in 200 c. c. of equal 
parts of absolute alcohol and ether. A thin solution is prepared 
by taking equal parts of the stock solution and the absolute 
alcohol and ether solution. 



A LABORATORY GUIDE IN HISTOLOGY. 115 

D. Clearing Fluids. 

Purposes of a clearing oil. The oil removes the alcohol, 
renders the section more transparent, and is a solvent for the 
mounting media. 

(1) Oil of Cloves. 

Clears quickly, does not spread over the slide, and renders 
the sections somewhat brittle. Dissolves celloidin. Clears from 
95% alcohol. 

(2) Oil of Bergamot. 

Clears quickly from 95% alcohol. Does not destroy aniline 
stains. Does not dissolve celloidin. 

(3) Oil of Origanum. 

Does not dissolve celloidin if good. Clears from 95% alcohol. 

(4) Phenol. 

Clears quickly and does not dissolve celloidin. 

(5) Eycleshymer's Mixture. 

Oil of cedar, one part. 
Oil of bergamot, one part. 
Phenol crystals, one part. 
Does not dissolve celloidin, clears rapidly from 95% alcohol, 
and is a splendid clearing agent. 

(6) Eycleshymer's Nerve Mixture. 
Oil of cedar, 50 c. c. 

Oil of bergamot, 50 c. c. 
Phenol crystals, 25 grams. 

(7) Phenol-xylol Mixture. 

Phenol crystals, one part. 
Xylol, three parts. 

(8) Xylol. 

Clears rapidly after chloroform or absolute alcohol, but not 
after 95% alcohol. Used on paraffin sections only. 

(9) Ether-Alcohol. 

Take equal parts of ether and o\ absolute alcohol. 



n6 A LABORATORY GUIDE IN HISTOLOGY. 



The Typical Cell. 

I. 1 Definition. — A unit mass of protoplasm (living matter) 
having a nucleus. 

2. 1 Parts. 

I. 2 Cell wall — always a cell product. 
2. 2 Cell body or cytoplasm. 
I. 8 Structure. 

i.* A fluid matrix or ground substance, hyaloplasm or 

cytolymph. 
2. 4 A formed element or spongioplasm. Structure not 
fully understood. The essential element of the 
cytoplasm. 
I. 5 Altmann's granule theory. 
2. 5 Fibrillar theory. 
3. 5 Biitchli's foam or emulsion theory. 
2. 3 Cell inclusions. 

I. 4 Vacuoles. — Spherical spaces containing a fluid of 
different consistence from that of the surrounding 
cytoplasm. 
2. 4 Secretory granules. — Glycogen, mucinogen, zymo- 
gen, etc. 
3. 4 Forms of pigment, fat, excretory substances, etc. 
3. 2 Nucleus. 
I. 3 Definition. 
2. 3 Structure. 

I. 4 Nucleoplasm or nuclear matrix. 
2. 4 Nucleoreticulum. 

i. 5 Chromatic part. Chromatin masses, granules, 

threads, or chromosomes. 
2. 5 Achromatic part. A network of fine linin threads 
embedded in the nucleoplasm. 
3.* Nuclear membrane. 
4. 4 Nucleolus. 

I. 5 Definition, structure, and function. 
4. 2 Centrosome and attraction sphere. 
i. 3 Location, structure and function. 



A LABORATORY GUIDE IN HISTOLOGY. 117 

3. 1 Cell motion. 

i. 2 Amoeboid locomotion. — Due to action of cell processes 

or pseudopodia. 
2. 2 Ciliary. 

i. 3 Nature of cilia. 
2. 3 Waves of ciliary movement. 
3. 2 Undulatory. — That of the flagella of sperm cells. Closely 

allied to ciliary movement. 
4. 2 Molecular motion of granules in the cytoplasm. 

(Brownian). 
5. 2 Protoplasmic currents within the cell. 

4. 1 Cell growth. 

i. 2 Definition of growth. 

2. 2 Manner of growth. 

3. 2 Manner of growth limitation. 

4. 2 Effect of growth upon the form of cell. 

5. 1 Cell properties, i.e., the properties of living matter or pro- 
toplasm. 
i. 2 Partial definitions of life. 
2. 2 Chemical composition of protoplasm. — A mixture of 

complex proteins. 
3. 2 General properties. 

i. 3 Irritability. — Capability of responding to a stimulus. 
2. 3 Contractility. — A reaction to a stimulus shown usually 

by a. change in form. 
3. 3 Metabolism. — Distinguishes the living from the non- 
living. 
4. 3 Growth and function. 
5. 3 Reproduction. 

6. 1 CeM reproduction. 
I. 2 Methods. 

i. 3 Amitotic or direct. — Rarely occurs normally in the 

higher forms of life. 
2. 3 Mitotic, indirect, or karyokinetic. 

i. 4 Stages. — The process of cell division is a continuous 
one but for convenience in description it is usually 
divided into four stages which arc not sharply 
differentiated in all cases. 



n8 A LABORATORY GUIDE IN HISTOLOGY. 

i. 5 Prophases or stages of preparation. 
i. 6 Disappearance of nuclear membrane. 
2. c Disappearance of nucleolus. 
3. 6 Chromatin masses unite to form the mother 

skein or spirem. 
4. 6 Formation of the chromosomes. 

I. 7 The number of chromosomes is always fixed 

and characteristic for a given species. 
2. 7 Always even in sexual form of reproduction. 
3. 7 The bearer of the hereditary traits. 
5. 6 Division and separation of the centrosome. 
6. 6 Formation of the central spindle and the polar 

rays. 
7. 6 Chromosomes arranged to form the monaster. 
2. 5 Metaphases. 

i. 8 Longitudinal splitting of the chromosomes. 
2. 6 Metakinesis and formation of the diaster. 
i. 7 Probable action of the mantle fibers. 
3. 5 Anaphases. 

i. 6 Chromosomes form chromatin threads. 

2. 6 Chromatin masses form as in the resting 

nucleus. 
3. 6 Nuclear membrane forms. 
4. 5 Telophases. 

i. 6 Division of cytoplasm occurs. 

2. 6 Daughter nuclei and centrosomes assume the 

normal position. 
3. 6 Changes of the prophase in reverse order. 



Fertilization. 

I. 1 Definition. — The union of the male pronucleus with the 
female pronucleus. 

2. 1 Purpose. 

3. 1 Preparation of germ cells. 
i. 2 Maturation of sperm cell. 

i. 3 Definition. — The process of division resulting in the 
reduction of the chromosomes to one-half those of 



A LABORATORY GUIDE IN HISTOLOGY. 119 

a somatic cell nucleus. The resulting nucleus is 

the male pronucleus. 
2. 3 How reduction is accomplished. 
3. 3 Purpose of reduction. 
2. 2 Maturation of egg cell. 

i. 3 Comparison with that of the sperm cell. 

2. 3 Purpose of reduction. 

3. 3 Female pronucleus thus formed. 

4. 1 Changes in male and female pronuclei. 
i. 2 Loss of nuclear membranes. 

2. 2 Intermingling of chromosomes of the pronuclei. 
3. 2 Formation of a monaster. 
4. 2 Division of male centrosome. 
5. 2 Longitudinal cleavage of chromosomes. 
6. 2 Formation of diasters. 

J. 2 Formation of two daughter cells (segmentation of 
ovum.) 

i. 3 Formation of blastomeres and blastoderm. 

2. 3 Formation of two primary germ layers. 

3. 3 Formation of three primary germ layers. 



Tissues. 

I. 1 Definition. — A structural association of certain types of 
cells with certain types of intercellular substance. 

2. 1 Composition. 

i. 2 Composed of cells and intercellular substance (cell 
product). 

3. 1 Origin from germ layers. 
i. 2 From the ectoderm. 
2. 2 From the mesoderm. 

i. 3 Sub groups of mesoderm. 

i. 4 Mesothelium. 

2. 4 Mesenchyme. 

3« 4 Mesamceboid. 

3.- From the endoderm. 



120 A LABORATORY GUIDE IN HISTOLOGY. 

4. 1 Classification. 

I. 2 No scientific classification possible at present. 

2. 2 Tissues morphologically similar derived from different 

germ layers. 
3. 2 Fundamental tissues. 

i. 3 Epithelium. 

2. 3 Mesenchyma. 
4. 2 Subdivisions of adult tissues. 

i. 3 Epithelium. 

2. 3 Connective tissues. 

3. 3 Blood and lymph. 

4. 3 Muscular. 

5. 3 Nerve. 

The Connective Tissues. 

1. 1 Definition. 

2. 1 Histogenesis. 

3. 1 General characteristics. 

I. 2 Predominance of intercellular elements. 

2. 2 Physical properties given to tissue by the intercellular 

substance. 
3. 2 Cellular elements relatively unimportant. 

4. 1 General structure. 

i. 2 Matrix or ground substance. 
2. 2 Fibrillar structures. 
i. 3 White fibers. 

i. 4 Structure and characteristics. 
2. 3 Yellow fibers. 

i. 4 Structure and characteristics. 
3. 2 Cells. 

i. 3 Fixed connective tissue cells. 
i. 4 Spindle cells. 
2. 4 Pigment cells. 
3. 4 Lamellar cells. 
4. 4 Mast cells. 
5. 4 Plasma cells. 
6. 4 Fat cells. 
2, 3 Wandering cells (leucocytes). 



A LABORATORY GUIDE IN HISTOLOGY. 121 

- 1 Classification. 
i. 2 Embryonic and mucous. 

i. 3 Developmental types with cellular elements predom- 
inating. 
2. 2 Elastic. 

I. 3 Structural characteristics. 
3. 2 White fibrous. 

i. 3 Structure. 
4. 2 Reticular. 

I. 3 Structure and location. 
5. 2 Adipose. 

i. 3 Formation and structure of fat cells. 
2. 3 Structure of adipose tissue. 
3- 3 Chemical tests for fat. 
4. 3 Blood supply. 
6. 2 Adenoid or lymphoid. 

i. 3 Structure. 
J. 2 Cartilage. 

i. 3 General structure. 
I. 4 Matrix. 
2. 4 Cells. 
3. 4 Perichondrium. 
4. 4 Blood supply. 
2. 3 Varieties. 
i. 4 Embryonic. 

I. 5 Histology. 
2. 4 Hyaline. 
i. 5 Histology. 
2. 5 Location. 
3. 4 White fibrous. 
i. 5 Histology. 
2. 5 Location. 
4. 4 Elastic. 
i. 5 Histology. 
2. 5 Location. 
8. 2 Bone. 

I. 3 Definition. 
2. 3 Histology. 

i. 4 Compact bone. 



122 A LABORATORY GUIDE IN HISTOLOGY. 

i. 5 Haversian system. 
i. 6 Composition. 

i. 7 Haversian lamellae. 
2. 7 Lacunae and bone cells. 
3. 7 Canaliculi. 

4. 7 Haversian canal for vesssels and nerves. 
2. 5 Intersystemic or interstitial. 

i. 6 Structure. 
3. 5 Circumferential bone. 
i. 6 Outer or subperiosteal. 
2. 6 Inner or endosteal. 
4. 5 Periosteum. 

i. 6 Layers and structure. 
2. 6 Function. 
5. 5 Blood supply. 

i. 6 Volkmann's canals. 
2. 6 Haversian canals. 
3. 6 Nutrient foramen. 
2. 4 Spongy bone. 
i. 5 Structure. 
3. 3 Development. 
i. 4 Forms. 

i. 5 Intramembranous. 

i. 6 Formation of ossific centers. 
2. 6 Development of periosteum. 
2. 5 Intracartilaginous. 

i. 6 Development of centers of calcification in the 

cartilage. 
2. 6 Development or change of the perichondrium 

into the periosteum. 
3. 6 Ingrowth of periosteal buds. 
4. 6 Absorption of calcified cartilage and formation 

of spongy bone. 
5. 6 Formation of primary marrow spaces. 
6. 6 Formation of the Haversian systems. 
7. 6 Formation of the intersystemic bone. 
8. 6 Formation of the medullary cavity. 
9. 6 Formation of the endosteum. 
io. 6 Formation of the circumferential lamellae. 



A LABORATORY GUIDE IN HISTOLOGY. 123 

I. 7 Outer from the osteoblasts of the periosteum. 
2. 7 Inner from the osteoblasts of the endosteum 
lining the marrow cavity. 



The Blood. 

1. 1 Histological definition. 

2. 1 Histogenesis. 

i. 2 Formation of "blood islands." 

2. 2 Formation of erythrocytes. 

3. 2 Formation of leucocytes. 

4. 2 Formation of thrombocytes or platelets. 

3. 1 Histology. 

i. 2 Intercellular substance or plasma. 
2. 2 Formed elements. 
i. 3 Erythrocytes. 

i. 4 Size, form, color, number, etc. 
2. 4 Structure. 
i. 5 Stroma. 

i. 6 Not homogeneous or structureless; opinions 
differ; has an outer limiting layer (exoplasm) 
insoluble in water and permitting a very free 
osmosis as is shown by the changes occuring 
in the cell with changes in the density of the 
blood plasma. The effect of reagents upon 
the cells shows that they are exceedingly 
sensitive to such changes of density in the 
plasma. 
2. 5 Hemoglobin. — An iron-bearing protein body. 
i. 6 Relation to the stroma. 

I. 7 Partly in solution in the stroma, partly in a 
more intimate chemical combination. (G. N. 
Stewart.) 
2. 6 Crystallization. 

i. 7 Hemoglobin crystals. 
2. 7 Hemin crystals. (Teichmaiin.) 
2. 3 Leucocytes. 
I. 4 Structure. 



i2 4 A LABORATORY GUIDE IN HISTOLOGY. 

2. 4 Varieties according to number and form of nuclei. 
i. 5 Mononuclear. 

i. 6 Lymphocytes. — Characteristics and number. 
2. 6 Leucocytes. — Characteristics and number. 
3. 6 Transitional. — Characteristics and number. 
4. 6 Polymorphonuclear. — Characteristics and num- 
ber. 
2. 5 Multinuclear or polynuclear. — Characteristics and 
number. 
i. 6 Relation to leucocytes 3 6 and 4 above. 
3. 4 Varieties according to granules in the cell body. 
i. 5 Acidophile or Eosinophile. From 1-4% in normal 

blood. 
2. 5 Amphophile. — Xot found in normal blood. 
3. 5 Basophile. — Found in mast cells. Rare in normal 

blood. 
4. 5 Neutrophile. — Polynuclear and polymorphonu- 
clear types, about 70% of all leucocytes. 
3. 3 Thrombocytes or platelets. 

i. 4 Size, number, structure, function, and origin. 



The Blood Vascular System. 

1. 1 Structures of. — Heart, arteries, capillaries and veins. 

2. 1 Histology. 

i. 2 Continuous endothelium. 
2. 2 Structure of vessels. 
i. 3 Arteries. 

I. 4 Medium-sized. 

i. 5 Tunica intima — internal coat. — Xon-vascular 
i. 6 Endothelium. 

2. 6 Subendothelial connective tissue layer. 
3. 6 Internal elastic limiting layer. 
2. 5 Tunica media — middle coat. — Thickest coat. 
i. 6 Arrangement of muscle. 
2. 6 Arrangement of connective tissue. 
i. 7 Sinuous folds of the elastic tissue. 



A LABORATORY GUIDE IN HISTOLOGY. 125 

3. 5 Tunica adventitia — external coat. 
I. 6 Composition. — Chiefly white fibers. 
2. 6 External elastic limiting layer. (This layer 
may be considered as belonging to the tunica 
media). 
3. 6 Arrangement of connective tissue. 
4. 6 Vasa vasorum. 
5. 6 Nervi vasorum. 
2. 4 Large arteries. — Typically elastic. 

I. 5 Layers less distinct -than in medium sized arteries. 
Elastic limiting layers not distinct. 
Preponderance of elastic tissue in the media. 
Walls relatively thin. 

Comparison of coats with those of a medium sized 
artery. 
3. 4 Small artery or arteriole. — Typically muscular. 
I. 5 Structure of tunics. 
2. 5 Comparison of tunics with those of the medium 

sized arteries. 
3. 5 Well defined muscular layer of tunica media. 
I. 6 Distribution of the vaso-motor nerves. 
4. 4 Precapillary artery. 

i. 5 Tunica intima, the endothelial lining. 
2. 5 Isolated muscle cells of tunica media. 
3. 5 Loose connective tissue of the adventitia. 
. 3 Capillaries. 

. i. 4 Wall consists of endothelium. 
2. 4 Structural tracing to precapillary arteries and post 

capillary veins. 
. 3 Veins. 
i. 4 Structure of wall not dependent upon the size of the 

vessel. 
2. 4 Coats not distinctly differentiated. 
3. 4 Subdivisions. 

I. 5 Postcapillary venule. 
I. 6 Endothelial lining. 
2. c Delicate connective tissue sheath. 
2. 5 Small vein. 



126 A LABORATORY GUIDE IN HISTOLOGY. 

i. 8 Tunica intima. — Non-vascular. 

i. 7 Structure. 
2. 6 Tunica media. 

I. 7 Structure. 
3. 6 Tunica adventitia. 
i. 7 Structure. 
3. 5 Large veins. 

i. 6 Tunica intima. — Non-vascular. 

I. 7 Endothelium and subendothelial connective 
tissue layer, 
2. G Tunica media. 

I. 7 Comparison with that of the arteries. 
3. 6 Adventitia. 
i. 7 Structure. 
2. 7 Vessels and nerves. 
4. 4 Structure of the valves. 
4. 3 Heart. 

i. 4 A modified portion of a blood vessel. 
2. 4 Layers of wall. 

i. 5 Epicardium. — Visceral layer of the pericardium. 

i. 6 Structure. 
2. 5 Myocardium. 

i. 6 Characteristics of muscle cells. 
2. 6 Arrangement of muscle. 

i. 7 Endomysium of myocardium. 
3. 6 Connective tissue increased in certain situations. 
3« 5 Endocardium. 
i. 6 Structure. 
3. 4 Structure of valves of the heart. 
4. 4 Blood and nerve supply. 



Bone Marrow (Medulla ossium). 

i. 1 Definition. 
2. 1 Kinds. 
i. 2 Red. 

i. 3 Development. 
2. 3 Histology. 



A LABORATORY GUIDE IN HISTOLOGY. 127 

i. 4 Types of cells. 

i. 5 Myelocytes or marrow cells. 

i. 6 Lymphocytes. — -Deeply staining ovoid nucleus. 
2. 6 Mononuclear marrow cells. — Faintly staining 

ovoid nucleus. 
3. 6 Polynuclear neutrophiles. 
4. 6 Eosinophile marrow cells. 
2. 5 Mast cells. — Basophile granules, polymorphous 

nucleus. 
3. 5 Giant cells (Myeloplaxes). 

I. 6 Polykaryocyte. — Multinuclear, identical with 

the osteoclasts. 
2. 6 Megakaryocyte. — Polymorphous nucleus. 
3. 6 Formation of giant cells. 
4. 5 Erythroblasts or nucleated erythrocytes. 
I. 6 Characteristics. 
2. 6 Types. 

i. 7 Normoblasts. 
2. 7 Microblasts. 
3. 7 Megaloblasts. 
5. 3 Erythrocytes. 

6. 5 Blood platelets or thrombocytes. 
7. 5 Fat cells. 
8. 5 Osteoblasts. 
2. 4 Fibrous and reticular tissue. 
3. 3 Blood supply. Terminate in sinusoids lined through- 
out by endothelium. 
2. 2 Yellow. — Consists largely of fat, formed from the red 

marrow. 
3. 2 Gelatinous. — The marrow of old age and of certain 
pathological conditions. 

The Lymphatic Organs. 

1. 1 Lymph nodes. 
i. 2 Structure. 
i. 3 Framework. 

I. 4 Capsula fibrosa. 
2. 4 Trabecular. 



128 A LABORATORY GUIDE IN HISTOLOGY. 

I. 5 Primary. . 
2. 5 Secondary. 
3. 5 Tertiary. 
3. 4 Reticulum. 
2. 2 Hilum. 
3. 2 Parts. 
I. 3 Cortex. 

I. 4 Arrangements of lymph nodules. 
2. 4 Structure of nodules or follicles. 

i. 5 Germinal center. 
3. 4 Lymph sinuses. 
i. 5 Location. 
2. 5 Formation. 
2. 3 Medulla. 

i. 4 Smaller compartments than in cortex. 

2. 4 Lymph cords. — From follicles of cortex to medulla 

where they anastomose freely. 
3. 4 Lymph sinuses. 
3. 3 Relation of lymph sinuses to afferent and efferent 
lymphatics of the node. 
4. 2 Blood supply. 
5. 2 Lymphatics. 
6. 2 Nerves. 

2. 1 The Thymus. 
I. 2 Histogenesis. 

2. 2 Structure of early epithelial organ. 
3. 2 Conversion into a lymphoid structure. 
4. 2 Structure. 
i. 3 Capsule. 
2. 3 Lobes. 

3. 3 Lobules. — Units of structure. 
i. 4 Cortex. 

I. 5 Nodules or follicles compactly arranged. 
i. 6 Absence of true germinal centers. 
2. 4 Medulla. 

I. 5 Diffuse lymphatic tissue. 
2. 5 . Hassal's corpuscles. 
I. 6 Structure. 
2. 6 Interpretation. 



A LABORATORY GUIDE IN HISTOLOGY. 129 

5. 2 Blood supply. 
6. 2 Nerves and lymphatics. 
3. 1 The Tonsils. 

i. 2 Palatine or True (Tonsillar palatinge). 
i. 8 Structure. 

i. 4 Fibrous capsule covers attached surface. 

i. 5 Trabecular. 
2. 4 Surface epithelium. 
3. 4 Crypts. 

I. 5 Primary and secondary. 
4. 4 Lymphoid Tissue. 
i. 5 Diffuse. 
2. 5 Nodular. 

3. 5 Lymphoid infiltration of epithelium. 
i. 6 Interpretation. 
2. 3 Blood supply. 
3. 3 Lymphatics. 
4. 3 Nerves. 
2. 2 Lingual Tonsils (Folliculi linguales). 
i. 3 Location. 
2. 3 Structure. — Similar to palatine tonsils. 

i. 4 Crypts may receive ducts of some lingual mucous 
glands. 
3. 2 Pharyngeal Tonsils. 

i. 3 Structure. 
4. 2 Development. 

i. 3 Of lymphatic tissue. 
2. 3 Of crypts. 
4. 1 The Spleen. 
I. 2 Structure. 
i. 3 Coverings. 

i. 4 Tunica serosa. 
2. 4 Tunica fibrosa. 
2. 3 Framework. 

3. 3 Splenic corpuscles. — Characteristic of the spleen. 
i. 4 Development. 
2. 4 Structure. 
4. 3 Splenic pulp. 



i'3o A LABORATORY GUIDE IN HISTOLOGY. 

i. 4 Cells. 

i. 5 Large mononuclear leucocytes. 
Lymphocytes. 
Polynuclear leucocytes. 
Eosinophiles. 
Basophiles. 
Giant cells. 
Erythrocytes. 
Erythroblasts. 
Thrombocytes. 
5. 3 Blood Supply. 

I. 4 Distribution of arteries. 
2. 4 Formation of veins. 
6. 3 Lymphatics. 
7. 3 Nerves. 

Muscular Tissue. 

i. 1 Histogenesis. 

2. 1 A tissue in which the property of contractility is greatly 
developed. 
I. 2 Muscle protoplasm contracts in but one direction. 
2. 2 Undifferentiated protoplasm contracts equally well in all 

directions. 
3. 2 Contractile elements are the sarcostyles (differentiated 
spongioplasm). 

3. 1 Varieties. 

i. 2 Non-striated or involuntary smooth. 
i. 3 Characteristics of cells. 
i. 4 Size and shape of cells. 
2. 4 Arrangement of the cells in the tissue. 
3. 4 Structure. 

i. 5 Sarcostyles and sarcoplasm. 
2. 5 Cell membrane (?). 
4. 4 Blood and nerve supply. 
2. 2 Striated. 

i. 3 Development. 

2. 3 Involuntary or cardiac. 



A LABORATORY GUIDE IN HISTOLOGY. 131 

i. 4 Structure of cells or units of structure. 

i. 5 Probably a syncitium in which cells are not sep- 
arated from each other. 
2. 5 Delicate connective sheaths surround the cells. 
3. 5 Explanation of striations. 
2. 4 Blood and nerve supply. 
3. 3 Voluntary or skeletal muscle-fibers. 
i. 4 Development. 
2. 4 Structure. 
i. 5 Sarcolemma. 

2. 5 Sarcostyles or contractile elements extend entire 
length of the fiber. 
i. 6 Segments. 

i. 7 Formation and structure of the segments. 
3. 5 Sarcoplasm. 
4. 5 Nuclei. 
5- 5 Cohnheim's areas. 
3.* Blood and nerve supply. 
4. 4 General structure of a muscle. 
I. 5 Epimysium. 
2. 5 Perimysium. 
3. 5 Endomysium. 
4. 5 Muscle fasciculi. 

The Teeth. 

* 

1. 1 Histogenesis. 
2. 1 Structure. 
i. 2 Enamel. 

i. 3 Enamel rods or prisms are the units of structure. 
I. 4 Probably extend through the entire thickness of the 

enamel. 
2. 4 Size, shape, markings, structure, etc. 
2. 3 Cement substance. 
3. 3 Parallel lines of Retzius. 
4. 3 Cuticula dentis. 

I. 4 Nature and formation. 
5. 3 Arrangement of enamel rods with reference to the 
dentine. 



132 A LABORATORY GUIDE IN HISTOLOGY. 

2. 2 Dentine. 

i. 3 Ground substance or matrix. 
i. 4 Fibrillar substance. 

2. 4 Interfibrillar substance containing the mineral salts. 
2. 3 Dentinal tubules. 

i. 4 Origin and course from the pulp chamber. 
2. 4 Branching and termination. 
3. 4 Dentinal fibers from the odontoblasts. 
4. 4 Interglobular spaces. 
3.- 1 Cementum. 

i. 3 Relation to the dentine. 



2. 


3 Structure. 


I. 
2. 


Pulp. 

3 Structure. 
3 Odontoblasts 



i. 4 Cell and processes. 
5. 2 Peridental membrane. 

I. 3 Structure and function. 
6. 2 Blood supply. 
J. 2 Nerves. 

1 Development. 

i. 2 Formation of enamel groove. 
2. 2 Formation of tooth cord and the enamel ledge. 
3. 2 Formation of enamel organs. 
i. 3 Structure of enamel organ. 
I. 4 Outer enamel cells. 

2. 4 Enamel pulp composed of stellate cells. 
3. 4 Inner enamel cells or adamantoblasts. 
i. 5 Formation of the enamel rods. 
2. 3 Function of enamel organ. 
4. 2 Formation of enamel organs for permanent teeth. 
5, 2 Development of dental papilla. 
i. 3 Structure of dental papilla. 
2. 3 Odontoblasts. 
3. 3 Formation of dentine. 
i. 4 Membrana preformativa. 
2. 4 Order of formation. 



A LABORATORY GUIDE IN HISTOLOGY. 133 

6. 2 Development of fangs. 

J. 2 Development of dental periosteum from dental sac. 

8. 2 Development of pulp. 

Glands. 

1. 1 Definition. 

2. 1 Development of multicellular glands. 

I. 2 Glandular epithelium is a downgrowth from the surface 
epithelium into the underlying connective tissue 
stroma. 
i. 3 Development of lumen in the epithelial cord. 
2. 3 Differentiation of cord to form the parts of the gland. 
2. 2 Formation of the vascular stroma. 

3. 1 General structure. 

I. 2 Epithelium resting upon membrana propria. 

2. 2 Duct system. 

3. 2 Richly vascular stroma. 

4. 1 Unicellular glands. — Goblet cells of mucous membranes. 
i. 2 Manner of formation. 

5. 1 Types according to form. (Histological types.) 
i. 2 Tubular. 

i. 3 Straight. — Example, the glandulse intestinales. 

2. 3 Coiled. — Example, the sweat glands. 

3. 3 Branched. — Example, the cardiac glands of stomach 

and uterine glands. 
4. 3 Compound. 

i. 4 Consists of several distinct duct systems leading into 

a common excretory duct. 
2. 4 Example. — The liver and kidneys. 
5. 3 Compound tubulo-acinar. 

i. 4 Similar to 4 3 above except that the secretory portion 

is somewhat dilated. 
2. 4 Examples — The salivary glands. 



i 3 4 A LABORATORY GUIDE IN HISTOLOGY. 

2. 2 Saccular or alveolar. 

I. 3 Simple. — Smallest sebaceous glands. Typically found 

• in the skin of amphibians. 
2. 3 Branched. — The majority of the sebaceous glands be- 
long to this type. 
3. 3 Compound. — Several duct systems emptying into a 
common discharging duct. 
I. 4 Example. — The mammary gland. 

6. 1 Parts. 

i. 2 Mouth, neck or duct, and secretory fundus. 

7. 1 Types according to secretion. (Physiological types.) 
i. 2 Mucous. 

i. 3 Characteristics of epithelium and position of nucleus. 
2. 3 Demilunes at base of mucous cells. 
I. 4 Function. 

i. 5 May be true secretory cells resembling the serous 

type. 
2. 5 May be primitive mucous secreting cells. 
3. 3 Properties of mucus. 
4. 3 Changes during rest and activity. 
2. 2 Serous. 

I. 3 Characteristics of epithelium. 
2. 3 Form and position of the nucleus. 
3. 3 Changes during rest and activity. 
3. 2 Comparison of serous and mucous cells. 

8. 1 General structure mucous membranes. 

i. 2 Surface epithelium. 

2. 2 Membrana propria. 

3. 2 Muscularis mucosae. Not always present. 

4. 2 Lamina or tunica propria. 

5. 2 Tela submucosa. 

6. 2 Blood and lymph vessels. 

J. 2 Nerves. 



A LABORATORY GUIDE IN HISTOLOGY. 135 



The Tongue (Lingua). 

1. 1 Development. — By a reflection of the oral mucous mem- 
brane so as to enclose a mass of muscle with fibers ar- 
ranged in three planes. 

2. 1 Musculature. 
i. 2 Intrinsic. 
2. 2 Extrinsic. 

3. 1 Mucous membrane. 
i. 2 Epithelium. 
2. 2 Corium or lamina propria. 

I. 8 Papillae or superficial layer of corium. 
I. 4 Primary and secondary. 
2. 4 General structure of papillae. 
3. 4 Varieties. 

i. 5 Filiform or conical. 

i. 6 Distribution. 
2. 5 Fungiform. 
i. 6 Structure. 

2. 6 Taste buds may be present. 
3. 6 Distribution. 
3. 5 Circumvallate. 

I. 6 Number, location, and arrangement. 
2. 6 Structure. 
3. 6 Taste buds. 
i. 7 Structure. 

4. 1 Glands. 

i. 2 Mucous and serous in corium and between muscles. 
2. 2 Serous glands of von Ebner. 
i. 3 Location. 

2. 3 Ducts empty into vallum or depression around the cir- 
cumvallate papillae. 
3. 2 Glands of Nnhn. 
5. 1 Blood supply. 
6. 1 Nerve supply. 



136 A LABORATORY GUIDE IN HISTOLOGY 

The Digestive System. 

1. 1 Parts. 
I. 2 Pharynx. 

i. 3 Nasopharynx or respiratory portion. 
i. 4 Epithelium. 
2. 4 Lamina propria. 
2. 3 Oro-pharynx. 
I. 4 Epithelium. 
2. 4 Lamina propria. 
3. 4 Musculature. 
2. 2 (Esophagus. 
i. 3 Coats. 

i. 4 Tunica mucosa. 
I. 5 Epithelium. 
2. 5 Lamina propria. 
3. 5 Muscularis mucosae. 
2. 4 Tela submucosa. 
i. 5 Glands and vessels. 
2. 5 Plexus submucosus (Meissne/i). 
3. 4 Tunica muscularis. 

i. 5 Characteristics in upper third. 
2. 5 Characteristics in middle third. 
3. 5 Characteristics in lower third. 
4. 5 Plexus myentericus (Auerbachi). 
4. 4 Tunica fibrosa. 

i. 5 Structure and function. 
3. 2 Stomach (Ventriculus). 
i. 3 Coats. 

i. 4 Tunica serosa. 

i. 5 Surface mesothelium. 
2. 5 Submesothelial connective tissue. 
2. 4 Tunica muscularis. 

i. 5 Outer longitudinal layer. 

2. 5 Inner circular layer. 

3. 5 Partial oblique layer near cardiac orifice. 

4. 5 Plexus myentericus (Auerbachi). 



A LABORATORY GUIDE IN HISTOLOGY. 137 

3- 4 Tela submucosa. 
i. 5 Structure. 
2. 5 No true glands present. 
3. 5 Plexus submucosus (Meissneri). 
4. 4 Tunica mucosa. 

i. 5 Muscularis mucosae. 

2. 5 Lamina propria. 

3. 5 Epithelium. Goblet cells probably absent in a 

normal healthy stomach. 
4. 5 Glands. 

i. 6 Fundus or Peptic Glands. 

i. 7 Type. — Simple and branched tubular. 
2. 7 Open into gastric crypts. 
3. 7 Very narrow lumen. 
4. 7 Cell types. 

I. 8 Chief. — Zymogen granules numerous dur- 
ing rest. 
2. 8 Parietal. Cytoplasm clear or slightly gran- 
ular. 
i. 9 Secretory canals. 
2. 9 Function. 
2. 6 Pyloric glands. 

I. 7 Branched tubular, tortuous in their course. 
2. 7 Zones. 

i. 8 Superficial with its gastric crypts. 

2. 8 Middle. — Broadest, contains ducts of 

glands. 
3. 8 Deep. — Contains the convoluted secreting 
parts of the pyloric glands. 
3.° Cardiac glands. 
i. 7 Location. 
2. 7 Characteristics. 
3. 7 Relation to oesophageal glands. 
2. 3 Blood supply. 
3. 3 Lymphatics and nerves. 
4. 2 Duodenum. 

I. 8 Tunica mucosa. 

i. 4 Epithelium — with cuticular membrane. 
2. 4 Glandulse intestinales. (Lieberkiihni). 



138 A LABORATORY GUIDE IN HISTOLOGY. 

3. 4 Lamina propria and valvulae conniventes. 
4. 4 Villi. 

i. 5 Structure. 
5. 4 Muscularis mucosae. 
2. 3 Tela submucosa. 
I. 4 Structure. 

2. 4 Glandulae duodenales (Brunneri). 
I. 5 Type and secretion. 

2. 5 Relation to glands of pyloric portion of stomach. 
3. 3 Tunica muscularis. 
4. 3 Tunica serosa and fibrosa. 
5. 2 Jejuno-ileum. 
i. 3 Coats. 

2. 8 Valvulae conniventes and villi. 
3. 3 Glands. 
4. 3 Lymphoid tissue. 

I. 4 Solitary follicles or nodules. 
2. 4 Peyers patches (Noduli lymphatici aggregati). 
5. 3 Comparison with the preceding parts of gastrointes- 
tinal tract. 
6. 2 Large intestine (Intestinum crassum). 
i. 3 Coats. 
i. 4 Tunica mucosa. 

I. 5 Comparable to deeper or glandular part of that of 
small intestine, hence there is a complete ab- 
sence of villi. 
2. 5 Intestinal glands. 
3. 5 Goblet cells very numerous. 
4. 5 Lymphoid tissue. 
5. 5 Muscularis mucosae. 
2. 4 Tela submucosa. 
3. 4 Tunica muscularis. 

I. 5 Taeniae coli formed from longitudinal fibers. 
4. 4 Tunica serosa. 
2. 3 Comparative histology of the parts of large intestine. 
3. 3 Nerve supply. 
4. 3 Blood supply. 



A LABORATORY GUIDE IN HISTOLOGY. 139 

Respiratory System (Apparatus respiratoriusj. 

1. 1 The nares. 
i. 2 Regions. 

i. 3 Vestibular (vestibulum nasi). 
I. 4 Tunica mucosa. 
I. 5 Epithelium. 
2. 5 Lamina propria. 
2. 4 Tela submucosa or corium. 
i. 5 Papillae. 
2. 5 Glands. 
2. 3 Respiratory. 
I. 4 Epithelium 
2. 4 Lamina propria. 

3. 4 Stroma. — Lymphoid tissue and glands. 
4. 4 No true tela submucosa present. 
3. 3 Olfactory. 

I. 4 Distinguished by its color (brownish-yellow). 
2. 4 Tunica mucosa. 

I. 5 Epithelium. — Stratified columnar. 
i. 6 Sustentacular cells. 
I. 7 Parts of cell. 

i. 8 Superficial. — Cylindrical, pigment granules 
in longitudinal rows. 
I. 9 Membrana limitans olfactoria. 
2. 8 Nuclear zone or part containing the oval 

nucleus. 
3. 8 Protoplasmic process extending into deep- 
er cells. 
2. 6 Olfactory cells (ganglion cells). 
I. 7 Olfactory hairs. 
2. 7 Zone of round nuclei. 
3. 7 Axon as a centripetal nerve fiber. 
2. 5 Membrana propria indistinct. 
3. 4 Lamina propria or stroma. 
i. 5 Structure. 
2. 5 Glands (Bowmani). — Structure. 



140 A LABORATORY GUIDE IN HISTOLOGY. 



2 


- 1 Larynx. 




i. 2 General structure. 




2. 2 Histology. 




i. 3 Tunica mucosa. 




2. 3 Lamina propria. 




3« 3 Tela submucosa. 




4. 3 Laryngeal cartilages. 




5. 3 External fibrous tissue. 


3 


.* Trachea. 




i. 2 Tunica mucosa. 




I. 3 Epithelium. 




2. 3 Lamina propria. 




2. 2 Tela submucosa. 




3> 2 Tunica fibrosa and cartilages. 



4. 2 Blood and nerve supply. 

4. 1 Bronchi. 

I. 2 Structure of primary bronchi essentially similar to that 

of the trachea. 
2. 2 Changes in structure of secondary bronchi as they de- 
crease in size. 
I. 3 Change in epithelium. 

i. 4 Epithelium of medium sized bronchial tube. 
i. 5 Basal layer resting on membrana propria. 
2. 5 Middle or replacing layer. 
3. 5 Surface epithelium. 
2. 3 Change in the lamina propria (stroma). 
3. 3 Change in the muscularis mucosae. 
4. 3 Change in the tela submucosa. 
5. 3 Change in the cartilages. 

5. 1 The Lungs. 

i. 2 Structural resemblance to a racemose gland. 
2. 2 Tunica serosa. 
3. 2 Capsula fibrosa and its septa. 

4. 2 Unit of structure, the lobule, but lobulation is indistinct. 
Why? 
I. 3 Size, shape and structure of lobules. 



A LABORATORY GUIDE IN HISTOLOGY. 141 

2. 3 Arrangement of lobules. 

3. 3 Relation of terminal bronchus. 

i. 4 Formation of respiratory (terminal) bronchioles. 
i. 5 Formation of alveolar ducts. 
2. 5 Formation of atria. 
3. 5 Formation of air sacs. 
4. 5 Formation of air cells. 
2. 4 Characteristics of the epithelium of each part. 
5. 2 Blood supply. 

i. 3 Bronchial system. 

I. 4 Origin and distribution of the artery. 
2. 4 Found within the wall of the bronchus. 
3/ Relation between bronchial capillaries, bronchial 
veins, and pulmonary veins. 
2. 3 Pulmonary artery. 

i. 4 Relations to bronchial tubes. 
2. 4 Relation of branches to lung lobules. 
3/ Structures separating air and blood in the lungs. 
3. 3 Pulmonary veins. 

i. 4 Manner of formation. 
2. 4 Course and relation to the bronchioles. 
6. 2 Lymphatics. 
7. 2 Nerve supply. 



The Salivary Glands and Pancreas. 

I. 1 Small salivary glands. 

I. 2 Serous type. — von Ebner's of the tongue. 
2. 2 Mucous type. — Glands of Nuhn, the labial glands, the 
buccal, and the lingual. 
2. 1 Large salivary glands. Compound tubuloacinar type. 
i. 2 The parotid gland. 

I. 3 Purely serous in secretion. 

2. 3 Units of structure, the lobules, united firmly by con- 
nective tissue. 
i. 4 Acini. — Frequently branched or forked, relatively 
long. 



142 A LABORATORY GUIDE IN HISTOLOGY. 

i. 5 Characteristics of epithelium. 
2. 5 "Basket cells" well developed. 
3. 5 Lumen always narrow. 
3. 3 Ducts. 

I. 4 Subdivisions. 

2. 4 Lining epithelium stains readily with eosin. 
4. 3 Blood and nerve supply. 
2. 2 The submaxillary gland. 
i. 3 Mixed type as to secretion. 
2. 3 Histology of acini. 
I. 4 Lining epithelium. 
2. 4 Crescents of Gianuzzi. 
I. 5 Structural characteristics. 
2. 5 Significance. 
3. 4 Ducts. 
3. 3 Duct system. 
4. 3 Blood and nerve supply. 
3. 2 Sublingual gland. 

I. 3 Mucous or mixed (?) type. 
2. 3 Histology of acini. 
i. 4 Mucous cells. 
2. 4 Crescents of Gianuzzi. 
3. 3 Duct system. 
4. 3 Blood and nerve supply. 

3. 1 Pancreas. 

I. 2 Compound tubular type. 
2. 2 Capsule and trabecular. 

3. 2 Lobes and lobules not very distinct in human pancreas. 
4. 2 Excretory duct. — Extends lengthwise of the organ. 
i. 3 Short lateral branches to each lobule group. 
2. 3 Intralobular ducts, intermediate tubules, secreting 
tubules. 
5. 2 Secretory tubules. 

i. 3 Characteristics of epithelium. 

i. 4 Central and peripheral zones of the cells. 
2. 3 Changes during rest and activity. 
3« 3 Centro-acinar cells. — Significance. 



A LABORATORY GUIDE IN HISTOLOGY. 143 

6. 2 Cell islands of Langerhans. 

I. 8 Structure. 

2. 3 Significance. 
J. 2 Blood and nerve supply. 



The Liver (Hepar). 

1. 1 Nature. — A compound tubular gland with anastomosing 
secretory tubules. 

2. 1 Coverings. 

i. 2 Tunica serosa. 
2. 2 Capsula fibrosa. 

i. 3 Septa and trabecule. 

3. 1 Histology. 

i. 2 Unit of structure. — The lobules (Lobuli hepatis). 

I. 8 In man the lobules are not completely invested by 

connective tissue. 
2. 3 Size and shape of lobules. 
3. 3 Characteristics of hepatic cells. 

4. 3 Arrangement of blood and bile capillaries with regard 
to hepatic cells. 
2. 2 Portal canals. 

i. 3 Branch of hepatic duct. 

2. 3 Branch of hepatic artery. 

3« 3 Branch of portal vein. 

4. 3 Connective tissue sheath containing the lymphatics. 

4. 1 Blood supply. 

i. 2 Liver has a double blood supply. 
2. 2 Vessels concerned. 
i. 8 Hepatic artery. 
I. 4 Distribution. 

i. 5 Capsular branches to capsula fibrosa and its septse. 
2. 5 To vessels and structures of portal canals. 
3/' Capillaries may anastomose with capillaries of 
the lobule and with smaller branches of the in- 
terlobular branches of the vena porta?. 



144 A LABORATORY GUIDE IN HISTOLOGY. 

2. 3 Portal vein. 

I. 4 Formation. 

2. 4 Distribution. 

i. 5 Interlobar veins. 
2. 5 Interlobular veins. 
3. 3 Hepatic veins. 

I. 4 Origin in the vena centralis lobulse. 

2. 4 Sublobular veins. 

3. 4 Course of hepatic veins. 

4. 4 Relation of hepatic veins to liver tissue. 
4. 3 Intralobular capillaries. 

5. 1 Excretory duct (Ductus hepaticus). 
I. 2 Ductus biliferi (bile canaliculi). 
2. 2 Ductus interlobulares. 
3. 2 Structure. 

6. 1 The gall-bladder (Vesica fellese). 
i. 2 Histology. 

i. 3 Tunica mucosa. 

I. 4 Anastomosing rugae. 
2. 4 Epithelium. 
2. 3 Tunica muscularis. 
3. 3 Tunica serosa. 



The Urogenital System. 

(Apparatus urogenitalis.) 

i. 1 Parts. 

i. 2 Kidney (Ren). 

i. 3 Nature. — A glandular organ. 

2. 3 Coverings. 

., i. 4 Tunica adiposa. 

2. 4 Tunica serosa. 

3/ Tunica fibrosa. 

3. 3 Units of structure. 



A LABORATORY GUIDE IN HISTOLOGY. 145 

4. 3 Parts. 

i. 4 Substantia corticalis. 

i. 5 Pars radiata (Processus Ferreini). 
2. 5 Pars convoluta. 
2. 4 Substantia medullaris. 

i. 5 Pyramides renalis (Malpighii). 
i. 6 Nature of medullary substance. 
2. 6 Medullary rays. 
2. 5 Septa renis or columnar renales (Bertini). 
5. 3 Blood supply. 

i. 4 Aa. interlobares renis. 
2. 4 Arteriae archiformes. 
3. 4 Arteriae interlobulares. 

i. 5 Vas afferens to glomeruli. 
2. 5 Vas efferens from glomeruli. 
4. 4 Rami capsulares. 
5. 4 Arteriolar rectae. 
6. 4 Veins. 

i. 5 Vv. interlobares unite to form venae renis. 
2. 5 Venae interlobulares. 
3. 5 Venulae rectae. 
4. 5 Venae stellatae (Verheyni). 
6. 3 Tubuli uriniferi. 

i. 4 Corpuscula renis (Malpighii). 
i. 5 Glomerulus. 

2. 5 Capsula glomeruli (Bowmani). 
2. 4 Proximal convoluted tubule. 
3. 4 Descending limb of loop of Henle. 
4. 4 Loop of Henle. 
5. 4 Ascending limb of loop of Henle. 
6. 4 Distal convoluted tubule. 
7. 4 Arched or junctional tubule. 

8. 4 Collecting or discharging tubule (Ductus BelliniV 
9. 4 Foraminae papillariae. 

io. 4 Characteristics of epithelium of each part. 
2 Renal pelvis. 
i. 3 Tunica mucosa. 



146 A LABORATORY GUIDE IN HISTOLOGY. 

I. 4 Epithelium. — Transitional type. 

i. 5 Regeneration of epithelium. 
2. 4 Membrana propria. 
3.* Lamina propria. 

i. 5 Dense superficial layer. 

2. 5 Loose deep layer. Comparable to tela submu- 
cosa of gastrointestinal' tract. 
4. 4 So called pelvic glands but epithelial invaginations 
from the mucosa. 
2. 3 Tunica muscularis. 

i. 4 Arrangement of muscle. 
3. 3 Tunica fibrosa. 
4. 3 Blood and nerve supply. 
3. 2 Bladder. — Histology similar to that of the ureter. 
i. 3 Tunica mucosa. 

i. 4 Variation of character of epithelium in the distended 

and contracted state of the organ. 
2. 4 Glands absent except near urethral orifice. 
2. 3 Tunica muscularis. 
3- 3 Tunica fibrosa. 
4. 3 Tunica serosa. 
5. 3 Blood and nerve supply. 
4. 2 Urethra. 

i. 3 Male. (Urethra virilis). 
i. 4 Prostatic portion. 

I. 5 Transitional type of epithelium. 
2. 4 Membranous portion. 

i. 5 Epithelium is stratified columnar. 
3. 4 Penile or spongy portion. 

i. 5 Resembles that of the preceding part. 
4. 4 Part near meatus urinarius. 

I. 5 Epithelium changes to stratified squamous type. 
5. 4 Lamina propria. 

i. 5 Permeated by blood sinuses of the corpus spong- 
iosum. 
6. 4 Muscular tissue of urethra. 
2. 3 Female. (Urethra muliebris). 
• i. 4 Epithelium changes from transitional to stratified 
squamous. 



A LABORATORY GUIDE IN HISTOLOGY. 147 

2. 4 The epithelium of the midpart may resemble the 

stratified columnar type. 
3. 4 Lamina or tunica propria. — Rather dense areolar 
tissue. 
i. 5 Vessels so arranged as to form a sort of erectile 
tissue. 
4. 4 Few glands of mucous type near meatus urinarius. 
5. 4 Muscle cells. 



Male Genital Organs (Organa genitalia virilia). 

1. 1 Testis. 

i. 2 Tunica serosa. — Visceral layer of the tunica vaginalis 
testis, the parietal layer lining the scrotum. 
i. 3 Development. 
2. 2 Tunica albuginea. 
i. 3 Trabeculse or septse. 
2. 3 Mediastinum testis. 

3. 3 Relation of septse to tunica albuginea and to the medi- 
astinum testis. 
3. 2 Tunica vasculosa testis. 
4. 2 Unit of structure. — The lobule. 
I. 3 Tubuli seminiferi. 

I. 4 Tubuli seminiferi contorti. 
I. 5 Structure. 

i. 6 Layers of cells. 
i. 7 Spermatogones. 
2. 7 Spermatocytes. 
3. 7 Spermatids. 
4. 7 Spermatozoa. 

i. 8 Structure. 
5. 7 Sustentacular cells. (Sertoli.) 
2. 4 Tubuli seminiferi recti. 
3. 4 Rete testis. 
2. 3 Duct system. 

i. 4 Ductuli efferentes testis. 
i. r> Histology. 

i. 6 Epithelium. — Two varieties of cells. 



148 A LABORATORY GUIDE IN HISTOLOGY. 

2. 4 Coni vasculosi. 

i. 5 Formation and structure. 
3. 4 Epididymis. 

i. 5 Characteristics of epithelium of the canal. 

2. 5 Structure of membrana propria. 

3. 5 Arrangement of connective tissue. 

4. 5 Parts of epididymis. 
4. 4 Ductus deferens. 

i. 5 Structure of epithelium. 

2. 5 Structure of membrana propria. 

3. 5 Structure of tunica muscularis. 

4. 5 Outer fibrous coat. 
5. 2 Formation and maturation of the spermatozoa. 

2. 1 Vesicula seminalis. 
i. 2 Tunica mucosa. 

i. 3 Lining epithelium. Yellowish pigment in cells char- 
acteristic. 
2. 3 Foldings of mucosa. 

3. 3 Lamina propria. Processes extend into folds of the 
mucosa. 
2. 2 Tunica muscularis. 
3. 2 Functions. 

i. 3 Few or no spermatozoa present in most cases. 
2. 3 Secretion has a nutritive function for spermatozoa. 
4. 2 Blood and nerve supply. 

3. 1 Prostate. (Prostata). 

i. 2 Type. — Compound tubulo-acinar. 
2. 2 Structure. 

i. 3 Stroma and capsule. 

i. 4 Structure. Abundance of muscle characteristic. 
2. 4 Relation of muscle fibers to sphincter fibers of the 
urethra. 
2. 3 Glandular epithelium. 
i. 4 Type of cells. 
2. 4 Characteristic of cells. 
3. 4 Membrana propria. 



A LABORATORY GUIDE IN HISTOLOGY. 149 

4. 4 Epithelial foldings. 

i. 5 Especially well developed in the dog. 
2. 5 Varies in the different tubules. 
5. 4 Contents of the lumen. 
6. 4 Ducts. 

i. 5 Structural characteristics. 
3. 2 Blood supply. 
4. 2 Nerve supply. 
5. 2 Function. 

4. 1 Cowper's gland (glandula bulbourethralis). 
I. 2 Type. — Tubuloacinar. 
2. 2 Unit of structure. — The lobule. 
3. 2 Acini. 

i. 3 Structure. 

i. 4 Characteristics of epithelium. 
4. 2 Stroma. 
5. 2 Ducts. 

6. 2 Blood and nerve supply. 
J. 2 Function. 

5. 1 Penis. 

i. 2 General anatomy. 
2. 2 Structure of corpora cavernosa. 
3. 2 Structure of corpus spongiosum. 
zj. 2 Blood supply of erectile tissue. 
5. 2 Structure of glans penis. 

I. 8 Glands. 
6. 2 Nerve supply. 

I. 8 Tactile corpuscles. 
i. 4 Forms. 
2. 4 Structure. 

Female Reproductive Organs. 

(Organa genitalia muliebria). 

i. 1 Ovary (Ovarium). 

i. 2 General anatomical relations. 
2. 2 Development. 
3. 2 Histology. 



150 A LABORATORY GUIDE IN HISTOLOGY. 

i. 3 Medulla and hilum. 

i. 4 Structure. 

I. 5 Stroma. 

2. 5 Vessels. 

2. 3 Cortex. 

I. 4 Structure. 

i. 5 Stroma. 

I. 6 Tunica albuginea. 
2. 6 Theca folliculi. 
2. 5 Ova. 

i. 6 Development. 

I. 7 Germinal epithelium. 

i. 8 Development of primitive ova. 
2. 7 Formation of "egg tubes," better egg cords. 
3/ Formation of egg nests. 
4. 7 Formation of theca folliculi. 
5. 7 Formation of primitive follicle. 
2. 6 Growth of ovum and follicle. 
i. 7 Structure. 

i. 8 Theca folliculi. 
i. 9 Tunica externa. 
2. 9 Tunica interna. 
2. 8 Stratum granulosum. 

i. 9 Discus proligerus (cumulus oophorus). 
i. 10 Corona radiata. 
3. 8 Antrum folliculi. 
4. 8 Liquor folliculi. 
3. 6 Structure of ovum. 
i. 7 Cell body. 
2. 7 Nucleus. 
3. 7 Zona pellucida. 
4. 6 Ovulation. 

i. 7 Factors causing rupture of the follicle. 
5. 6 Changes in follicle after extrusion of the ovum. 
i. 7 Formation of corpus hemorrhagicum. 
2. 7 Formation of corpus luteum. 
i. 8 Corpus luteum verum. 
i. 9 Structure. 
2. 9 Nature. 



A LABORATORY GUIDE IN HISTOLOGY. 151 

2. 8 Corpus luteum spurium. 
3/ Formation of corpus albicans. 
4. 2 Blood and nerve supply. 

1 Oviduct (tuba uterina). 
i. 2 Parts. 
2. 2 Tunica serosa. 
3. 2 Tunica muscularis. 

i. 3 Inner circular layer. 

2. 3 Outer longitudinal layer. 
4. 2 Tunica mucosa. 

I. 8 Lining epithelium. 

i. 4 Compare with that of corresponding part of epi- 
didymis. 

2. 3 Folds. 
5. 2 Structure of fimbria. 
6. 2 Blood supply. 

1 Uterus. 
i. 2 Coats. 

i. 3 Tunica serosa. 

2. 3 Tunica muscularis. 

i. 4 Arrangement of muscle fibers more indistinct than 

in other mammals. 
2. 4 Stratum supravasculare. — Irregularly longitudinal. 
3. 4 Stratum vasculare. — Bundles of interlacing fibers. 
4. 4 Stratum submucosum. — Fibers mostly longitudin- 
ally arranged. * 
3. 3 Tunica mucosa. 
i. 4 Lining epithelium. 
2. 4 Lamina propria. 

i. 5 Embryonal type of connective tissue, richly cel- 
lular. 
2. 5 Leucocytes. 
3. 4 Uterine glands. 
I. 8 Glands of body. 

I. 6 Tubular invaginations of the surface epithelium. 
2. Function. — Probably that of epithelial regen- 
eration. 



152 A LABORATORY GUIDE IN HISTOLOGY. 

3. 6 Shape. 
2. 5 Glands of cervix uteri. 

i. 6 Branched tubular with frequent dilatations. 
2. 6 Mucoid secretion. 
2. 2 Uterine cavity. 
3. 2 Blood supply. 
4. 2 Lymphatics. 
5. 2 Nerve supply. 
6. 2 The menstruating uterus. 
i. 3 Stages. 

i. 4 Vascular hypertrophy of mucosa. 
2. 4 Desquamative stage. 
3. 4 Stage of regeneration. 

4. 1 Vagina. 

I. 2 General anatomy. 
2. 2 Histology. 
i. 3 Coats. 

i. 4 Tunica mucosa. 
I. 5 Epithelium. 
2. 5 Membrana propria. 
3. 5 Lamina propria. 

i. 6 Vascular layer, or submucosa. 
4. 5 Papillae and rugae. 
2. 4 Tunica muscularis. 

i. 5 Inner circular and outer longitudinal layer. 
3. 4 Tunica fibrosa. 
i. 5 Structure. 
2. 3 Blood and lymph vessels. 
3. 3 Nerve supply. 



The Eye (Organon visus). 

1. 1 General parts. — The bulbus oculi and its appendages. 
i. 2 Eyeball or bulbus oculi. 

i. 3 Size, shape, location, and general relations. 
2. 3 Structure. 
i. 4 Coats. 



A LABORATORY GUIDE IN HISTOLOGY. 153 

i. 5 External or sclera and cornea. 
i. 6 The cornea. 
i. 7 Structure. 

i. 8 Anterior epithelium. 

i. 9 Structural characteristics. 
2. 8 Anterior elastic membrane, or ant. homo- 
geneous membrane. 
3. 8 Corneal substance proper (substantia 
propria cornese). 
i. 9 Lamellatecl layers of connective tissue. 
2. 9 Corneal cells or corpuscles. 
4. 8 Posterior homogeneous layer. 
5- 8 Posterior endothelium. 
2. 6 The sclera. 
i. 7 Layers. 

i. 8 Substantia propria. — Well developed white 
fibrous connective tissue layer with long- 
itudinal, or meridional, and equatorial 
bands. 
2. 8 Lamina fusca. 

i. 9 Structure. 
3. 8 Lamina cribrosa sclerae. 
2. 7 Blood and nerve supply. 
3.° The sclero-corneal junction. 
i. 7 Structure. 

2. 7 Relation to fibers of ciliary muscle. 
3. 7 Relation to canal of Schlemm. 
2. 5 Middle coat. 

i. 6 Composed of choroid coat, iris, and ciliary body. 
2. 6 Structure. 

i. 7 Of choroid coat. 

I. 8 Lamina suprachoroidea. 

i. 9 Structural characteristics. 
2. 8 Lamina vasculosa. 

i. 9 Structure. 
2. 8 Lamina capillaris. 
i. 9 Structure. 
2. 7 Of ciliary body. 

I. 8 Shape and general structure. 



154 A LABORATORY GUIDE IN HISTOLOGY. 

2. 8 Parts. 

I. 9 Ciliary muscle and the arrangement of its 

fiber sets. 
2. 9 Fibrous layer. 

i. 10 Structure and function. 
2. 10 Ciliary processes. 
3. 9 Ciliary epithelium (pars ciliaris retinae). 
i. 10 Structure. 
3. 7 Of iris. 
i. 8 Histology. 

i. 9 External epithelial layer. 
2. 9 Stroma. 

i. 10 Sphincter muscle of iris and dilator 
muscle of iris. 
3. 9 Internal epithelium (pars iridis retinae). 
2. s Blood supply. 
3. 5 The internal coat. 

i. 8 The retina (pars optica retinae). 
i. 7 Ora serrata. 
2. 7 Macula lutea and fovea centralis. 

I. 8 Structural characteristics. 
3. 7 Layers from without inward. 
i. 8 Layer of pigmented epithelium. 
2. 8 Layer of rods and cones. 
I. 9 The rods. 

i. 10 Structure. 
2. 9 The cones. 
i. 10 Structure. 



External limiting layer. 



Outer nuclear layer. 

Outer molecular layer. 

Inner nuclear layer. 

Inner molecular layer. 

Layer of ganglion cells. 

Layer of nerve fibers. 

Internal limiting layer. 
4. 7 Interpretation of the layers. 
5. 7 Supporting tissue of the retina. 
2. 4 Humors of the eye. 



A LABORATORY GUIDE IN HISTOLOGY. 155 

3. 4 Crystalline lens. 
I. 5 Structure. 
i. 6 Lens capsule. 
2. 6 Epithelium. 
3. 6 Substantia propria lentis. 

i. 7 Form and arrangement of the lens fibers. 
2. 5 Suspensory ligament. 
3. 3 Blood supply. 

Appendages. 
i. 3 Eyelids. 

i. 4 Cutaneous portion or layer. 
i. 5 Structural characteristics. 
2. 5 Meibomian glands. 

i. 6 Relation to the tarsal plate. 
2. 4 Conjunctival layer. 
i. 5 Epithelium. 
i. 6 Structure. 
2. 5 Corium. 
i. 6 Structure. 

2. 6 Glands. — The posterior tarsal. 
2. 3 Lachrymal Gland. 

i. 4 Location and relations. 
2. 4 Type. — Compound tubular. 
3/ Unit of structure. — The lobule. 
i. 5 Secretory acini. 

i. 6 Characteristics of epithelium. 
2. 6 Changes during rest and activity. 
3. 6 Stroma. 
4. 4 Duct system. 
5. 4 Blood and nerve supply. 



Organ of Hearing (Organon auditusl 

i. 1 Parts. 

i. 2 Pars externa (external ear so called). 
i. 3 Auricle. 
i. 4 Histology. 



156 A LABORATORY GUIDE IN HISTOLOGY. 

i. 5 Fibro-elastic cartilage framework. 
2. 5 Skin. 
3. 5 Glands. 
2. 3 Meatus acusticus externus. 
I. 4 Cartilaginous portion. 
2. 4 Inner osseous portion. 
3. 4 Lining skin. 

i. 5 Characteristics in cartilaginous part. 
2. 3 Characteristics in osseous part. 
4. 4 Glands. 
3. 3 Membrana tympani. 
i. 4 Layers. 
i. 5 Outer. 

i. 6 Structure. Skin continuous with that of the 
preceding part of the canal. 
2. 5 Middle. 

I. 6 Structure. Very closely woven fibers to form 
lamina propria. 
3. 5 Inner. 

I. 6 Structure. Simple cubical epithelium resting 
on a fibrous stroma. 
4. 3 Blood and nerve supply. 
2. 2 Pars intermedia (middle ear so called). 
3 Location and communications. 
3 Structure of walls. 
3 Contents. 
3 Fenestra rotunda. 
3 Eustachian tube (Tuba auditiva). 
i. 4 Hi-stology. 
I. 5 Epithelium. 
2. 5 Stroma or lamina propria. 
3. 5 Glands. 
4. 5 Lymph nodules. 
2. 4 Blood and nerve supply. 
Pars interna (internal ear so called). 
3 Osseous labyrinth. 
i. 4 Vestibule. 
2. 4 Semicircular canals. • 
3. 4 Cochlea. 



A LABORATORY GUIDE IN HISTOLOGY. 157 

i. 5 Structure. 

i. 6 Conical axis or modiolus. 
2. 6 Spiral canal and cupola. 
3.° Lamina ossea spiralis and hamulus. 
4. 6 Lamina membranacea spiralis and spiral liga- 
ment. 
5. 6 Scala vestibuli and scala tympani. 

i. 7 Communicate through the helicotrema. 
2. 3 Membranous labyrinth. 
i. 4 Vestibular portion. 

I. 5 Saccule and ductus reuniens. 
i. 6 Structure of walls. 
i. 7 Macula acustica. 

i. 8 Neuro-epithelium or "hair cells." 

i. 9 Auditory hairs, otoliths and otolithic 
membrane. 
2. 8 Sustentacular cells. 
2. 5 Utricle and endolymphatic duct. 
3- B Utriculosaccular duct. 
2. 4 Membranous semicircular canals. 

i. 5 Ampulla and crista acustica. 
3. 4 Cochlear duct. 
i. 5 Walls. 

I. 6 Upper or vestibular. Membrane of Reissner. 
2. 6 Outer. — By ligamentum spirale. 
i. 7 Crista basilaris. 

2. 7 Spiral eminence and external spiral sulcus. 
3. 6 Lower or tympanic. 
I. 7 By the spiral lamina. 
I. 8 Basilar membrane. 
2. 8 The tympanic covering. 
3. 8 Cochlear covering. 
2. 5 Organ of Corti. 
I. 6 Basilar membrane. 
2. Epithelium. 

t. 7 Pillar cells or sustentacular colls. 

I. 8 Outer and inner. Structure and location. 
I. 9 Corti's arches and tunnel. 



158 A LABORATORY GUIDE IN HISTOLOGY. 

2. 7 Auditory or hair cells. Inner and outer. 

i. 8 Structure. 
3/ Deiter's cells. Sustentacular. 
4/ Hensen's cells. Sustentacular. 
3. 6 Membrana tectoria. 

I. 7 Location and structure. 
3. 3 Blood supply. 
4. 3 Lymphatics. 

i. 4 Perilymphatic spaces. 
2. 4 Endolymphatic spaces. 
5. 3 Nerve supply. 

i. 4 Vestibular branch of auditory nerve. 
2. 4 Cochlear branch of auditory nerve. 
i. 5 Spiral ganglion. 
i. 6 Bipolar neurones. 

I. 7 Course and termination of axones. 
2. 7 Dendrites. — To auditory cells of organ of 
Corti. 



Organ of Smell (Organon olfactus). 

1. 1 Parts. 

I. 2 Olfactory mucosa. 
i. 3 Location. 
2. 3 Structure. 
I. 4 Epithelium. 

i. 5 Sustentacular cells. 

I. 6 Structure. 
2. 5 Olfactory cells. 

i. 6 Relation to sustentacular cells. 
2. 6 Structure. 
3. 5 Membrana propria. 
4. 5 Stroma. 
i. 6 Structure. 
2. 6 Glands of Bowman. 

i. 7 Structure and nature as to secretion. 
2. 2 Olfactory bulb. 



A LABORATORY GUIDE IN HISTOLOGY. 159 

I. 3 Composition. 
2. 3 Layers. 

I. 4 Layer of olfactory fibers. 
2. 4 Layer of olfactory glomeruli. 
3.* Molecular layer. 
4. 4 Mitral cell layer. 
i. 5 Dendrites. 

2. 5 Axones to olfactory tract. 
5. 4 Granule layer. 
6. 4 Layer of longitudinal fibers. 
3- 2 The olfactory tract. 
4. 2 Reception nuclei of tract. 



The Skin (Cutis). 

I. 1 Development of the skin. 

2. 1 Layers. 
i. 2 Epidermis. 
i. 3 Layers. 

i. 4 Stratum cylindricum, 
2. 4 Stratum spinosum. 

i. 5 Intercellular bridges. 
3. 4 Stratum germinativum. 

i. 5 Composed of stratum cylindricum and adjacent 
cells of the stratum spinosum. 
4. 4 Stratum granulosum. 

i. 5 Structure. (Keratohyalin granules). 
5. 4 Stratum lucidum. (Eleidin granules). 
6. 4 Stratum corneum. (Keratin). 
2. 3 Comparison of the layers in the skin from different 
parts of the body. 
2. 2 Dermis (corium). 

i. 3 Connective tissue matrix for the epidermis. 
2. 3 Layers. 

i. 4 Stratum papillaris. 

i. 5 Structure of a papilla. 
2. 5 Varieties of papilla:. 



160 A LABORATORY GUIDE IN HISTOLOGY. 

i. 6 Tactile. 
2. 6 Vascular. 
3. 5 Arrangement. 
2. 4 Stratum reticularis. 
I. 5 Structure. 
3. 2 Tela subcutanea. 
I. 8 Structure. 

3. 1 Pigmentation. 

4. 1 Appendages. 
i. 2 Glandular. 
i. 3 Sweat glands. 

I. 4 Form, location and structure. 
2. 4 Ducts. 
3. 4 Development. 
2. 3 Sebaceous. 

i. 4 Compound saccular, a few small simple saccular. 
2. 4 Ducts open on surface of skin. 
3. 4 Ducts open into the hair follicles. 
4. 4 Structure. 

i. 5 Secretion saccule. 

i. 6 Manner of formation of the secretion. 
2. 5 Neck and duct. 
5. 4 Development. 
2. 2 Nails (Ungues). 

i. 3 Represent an excessive development of the stratum 

lucidum. 
2. 3 Parts. 

i. 4 Body (corpus unguis). 
i. 5 Structure. 

i. 6 Stratum lucidum. 
2. 6 Stratum mucosum. 
2. 4 Nail root (radix unguis). 
i. 5 Nail matrix and lunula. 
3. 4 Nail bed. 

i. 5 Structure. 
4. 4 Nail groove. 
3. 3 Growth. 
4. 3 Development. 



A LABORATORY GUIDE IN HISTOLOGY. 161 

3. 2 Hairs (Pili). 
I. 3 Development. 

I. 4 Formation of hair germ and hair canal. 
2. 4 Formation of hair papilla. 
3. 4 Formation of hair bulb. 
4. 4 Formation of hair follicle. 
2. 3 Structure. 
i. 4 Shaft. 
i. 5 Cuticle. 
2. 5 Cortex. 

3. 5 Medulla. May be wanting or present only in 
part of the shaft. 
2. 4 Root. 

I. 5 Structure. 
3. 4 The root sheaths. 

i. 5 The epidermal sheath. 
I. 6 Inner root sheath. 
i. 7 Imbricated cuticle. 
2. 7 Mid layer (Huxley). 
3. 7 Outer layer (Henle). 
2. 6 Outer root sheath. 

i. 7 Continuous with stratum mucosum. 
2. 7 Structure. 
2. 5 The dermal sheath. 

i. 6 Inner glassy layer, a membrana propria. 
2. 6 Circular fibrous layer. 
3.° Longitudinal fibrous layer. 
4/ Hair papilla. 
i. 5 Structure. 
3. 3 Growth of hair. 
4. 3 Shedding of hair. 
5. 3 Regeneration of hair. 

The Mammary Gland. 

I. 1 Histogenesis. 

2. 1 Type.— Compound saccular. 
3. 1 Lobes and lobules. 



1 62 A LABORATORY GUIDE IN HISTOLOGY. 

4. 1 Structure. 

I. 2 Capsula fibrosa and septae. 
2. 2 Duct system. 

i. 3 Excretory. 

2. 3 Interlobar. 

3. 3 Interlobular. 

4. 3 Terminal or secretory. 
3. 2 Structure of secretory acini. 

i. 3 Epithelium. 
i. 4 Characteristics. 

2. 4 Formation and discharge of the secretion. 
4. 2 Histology of the inactive gland. 
5. 2 The mammary gland at the menses. 
6. 2 The mammary gland during pregnancy. 
y. 2 The actively secreting gland. 

5. 1 Blood supply. Lymphatics. 

6. 1 Nerve supply. 



The Ductless Glands. 

■ Thyroid. 

i. 2 General anatomy. 

2. 2 Structurally similar to a compound saccular gland. 

3. 2 Capsule and septse. 

4. 2 Structure of lobule. 

i. 3 Perilobular connective tissue. 

2. 4 Structure of secretory alveoli or acini. 
I. 5 Stroma. 
2. 5 Epithelial lining. 
I. 6 Chief cells. 
2. 6 Colloid cells. 

3. 6 Relation of chief and colloid cells. 
5. 2 Blood supply. 
6. 2 Lymphatics. 
7. 2 Nerves. 



A LABORATORY GUIDE IN HISTOLOGY. 163 

2} Parathyroids. 
I. 2 Histology. 

2. 2 Relation to thyroid. 

3. 1 Suprarenals or Adrenals. 
i. 2 Relations. 
2. 2 Histology. 

i. 3 General parts. 
i. 4 Cortex. 

i. 5 Capsula fibrosa and trabeculse. 
2. 5 Zones. 

i. 6 Zona glomerulosa just beneath the capsule. 
2. 6 Zona fasciculata. 
3. 6 Zona reticularis. Cells pigmented. 
2. 4 Medulla. 

i. 5 Cell groups and their arrangement. 
2. 5 Relation of cell groups to the blood vessels. 
3. 5 Acidophile and fatty types of cells. 
4. 5 Nerve ganglia. 
3. 2 Blood supply. 

i. 3 Capsular plexus and capsular arteries. 
2. 3 Cortical and medullary arteries. 
3. 3 Veins. 
4. 2 Lymphatics. 
5. 2 Nerve supply. 

i. 3 Relation of ganglia to the solar plexus. 
2. 3 Distribution of nerves to the gland. 



L 


Carotid gland. 1 


(Glomus 


carot: 


icum) 


I, 


2 Location. 








2 


. 2 Histology. 

i. 3 Stroma. 

2. 3 Cell masses. 
i. 4 Origin of 
2. 4 Nature of 
3. 4 Structure 


cells, 
cells, 
of cells. 








4/ "Chromofi 


ne reaction." 





3. 2 Blood and nerve supply 



i6 4 A LABORATORY GUIDE IN HISTOLOGY. 

5. 1 Coccygeal gland. (Glomus coccygeum). 
i. 2 Location. 

2.' 2 Relation to A. sacra media. 
3. 2 Structure. Very similar to that of the carotid body. 

6. 1 Hypophysis cerebri. 
i. 2 Location. 
2. 2 Structure. 

i. 3 Posterior lobe. — Of nervous origin from the second 
cerebral vesicle. 
I. 4 Histology. 
2. 3 Anterior. 

i. 4 Diverticulum from cavum oris. 
2. 4 Histology. 

i. 5 Epithelial masses. Structural characteristics. 
2. 5 Sinusoids and capillaries. 
3. 2 Blood supply. 
-L 2 Nerve supply. 



Nervous Tissues. 

1*. 1 Histogenesis. 

2} L nit of structure. — The neurone. 
I. 2 Definition. 
2. 2 Parts. 

i. 3 Cell body. 

I. 4 Size, shape, and appearance. 
2. 4 Structure. 
I. 5 Cytoplasm. 
i. 6 Hyaloplasm. 
2. 6 Neurofibrils, modified or highly specialized 

spongioplasm. 
3.° Chromophilic bodies. 
4. 6 Pigment. 

2. 3 Nucleus and nucleolus. 

3. 3 Classes according to granule staining. (Nissl). 
I. 4 Somatochromes. 



A LABORATORY GUIDE IN HISTOLOGY. 165 

I. 5 Arkyochrome. 

i. 6 Chromophilic granules form a network. 
2. 6 Found in sensory nuclei of spinal cord and bulb. 
2. 5 Stichochrome. 

i. 6 Chromophilic bodies arranged in a linear man- 
ner. 
2. G Found in motor nuclei of cord and brain. 
3. 5 Gryochrome. 

i. 6 Chromophilic bodies clumped. 
2. 6 Found in the corpus striatum. 
4. 5 Arkyostichochrome. 

i. 6 Chromophilic bodies in linear reticulum. 
2. 6 Found in cells of Purkinje of cortex cerebelli. 
2. 4 Cytochromes. 

I. 5 Cytoplasm small in amount. 

2. 5 Found in granular layers of cortex of cerebrum 
and cerebellum. 
3.* Karyochrome. 

i. 5 Little cytoplasm; nucleus relatively large. 
2. 5 Found in granular layer of cortex cerebelli. 
4. 3 Dendrites, or so called "protoplasmic processes." 
i. 4 Structure. 
2. 4 Characteristics. 
5. 3 Axone or neuraxis. 
i. 4 . Structure. 
2. 4 Characteristics. 
3/ Collaterals. 

4. 4 Types according to length and distribution of neur- 
axis. 
i. 5 Golgi type I. 
I. 6 Definition. 
2. 5 Golgi type II. 
i.° Definition. 
3.- The nerve fiber. 

i. 3 Never a histological entity but a process of a nerve 

cell body. 
2. 3 Neuraxis or axone forms its essential part. 
3. 8 Classification. 



1 66 A LABORATORY GUIDE IN HISTOLOGY. 

I. 4 Medullated. 

i. 5 With a neurilemma. 

i. 6 Structure. 
2. 5 Without a neurilemma. 
i. 6 Structure. 
2. 4 Non-medullated. 

i. 5 With a neurilemma. 

i. 6 Structure. 
2. 5 Without a neurilemma. 
i. 6 Structure. 
4. 3 Nerves or nerve trunks. 
I. 4 Epineurium. 

2. 4 Perineurium surrounding the funiculi. 
3. 4 Endoneurium. 
4. 4 Blood supply. 
5. 3 Peripheral terminations. 
I. 4 Definition. 
2. 4 Function. — Change stimuli to "nerve impulse" or 

vice versa. 
3. 4 Connected with both motor and sensory fibers. 
4. 4 All terminations and origins "naked." 
5. 4 Classes. 

I. 5 Intraepithelial. 

I. 6 End fibrils. — Relation to epithelial cells. 
2. 6 Tactile cells. 

i. 7 Structure and location. 
3. 6 Neuro-epithelial. 

i. 7 Structure and location. 
4. 6 Taste buds. 
i. 7 Structure. 

i. 8 Gustatory cells. 
2. 8 Sustentacular cells. 
2. 7 Location. 
2. 5 Endings in connective tissues. 
i. 6 Tactile corpuscles (Meissneri). 
I. 7 Structure. 
2. 7 Location. 



A LABORATORY GUIDE IN HISTOLOGY. 167 

2. 6 End bulbs of Krause. 
i. 7 Structure. 
2. 7 Location. 
3. 6 Lamellar corpuscles (Pacinian). 
i. 7 Structure. 
2. 7 Location. 
4. 6 Corpuscles of Herbst. 

i. 7 Structure and location. 
5. 6 Corpuscles of Grandry (Merkel). 
i. 7 Structure and location. 
3. 5 Endings in muscle. 
i. 6 Motor end plates. 
I. 7 Structure. 

i. 8 Granular sole and nuclei. 
2. 8 Nerve ending. 
2. 6 Muscle spindles. 

i. 7 Concerned with the "muscular sense." 
2. 7 Structure. 
4. 5 Neurotendinous end organs. 
5. 5 Endings in cardiac and smooth muscle. 



Ganglia. 



I. 1 Definition. 

2. 1 Kinds. 
i. 2 Spinal. 

i. 3 Location and relation to dorsal root fibers. 
2. 3 Structure. 

i. 4 Capsule of fibrous tissue continuous with the peri- 
neurium or epineurium. 
2. 4 Trabeculse and framework. 
3. 4 Ganglion cells. 

i. 5 Size, shape, and general appearance. 
2. 5 Structure. 
3. 15 Processes. 
4. 4 Fibers ending in the ganglion. 
2. 2 Sympathetic. 



1 68 A LABORATORY GUIDE IN HISTOLOGY. 

I. 3 General location of ganglionic chains. 
2. 3 Structure. 

i. 4 Capsule and trabecular. 

2. 4 Structure of cells. 

3. 4 Fibers of ganglion. 
3. 2 Development. 

I. 3 Of spinal ganglia. 

2. 3 Of sympathetic ganglia. 

The Central Nervous System. 

i. 1 Development. 

i. 2 Ectodermic origin. 
2. 2 Formation of neural tube. 
I. 3 Structure of neural tube. 
I. 4 Differentiation of cells. 
i. 5 Spongioblasts. 

i. 6 Neuroglia proper. — Spider and mossy cells. 
2. 6 Ependyma. 
2. 3 Neuroblasts. 
3. 2 Formation of cerebral vesicles. 
i. 3 General development. 

2. 1 Subdivisions. 

i. 2 Spinal cord (Medulla spinalis). 
i. 3 Regions. 

i. 4 Division of regions into segments. 
2. 3 Enlargements. 

i. 4 Location and formation. 
3. 3 General structure. 
i. 4 White matter. 
2. 4 Gray matter. 

i. 5 Two symmetrical lateral masses connected by an 
intermediate portion or gray commissue. 
i. 6 "Horns" or columns of gray matter. 

i. 7 Anterior column. (Columna grisea anterior). 

i. 8 Characteristics at different levels. 
2. 7 Posterior column. (Columna grisea pos- 
terior). 
i. 8 Characteristics at different levels. 



A LABORATORY GUIDE IN HISTOLOGY. 169 

3/ Lateral column. 

i. 8 Cell groups. 

i. 9 Ventral. 

i. 10 Multipolar motor cells, axones passing 
into ventral root of the spinal nerves. 
2. 9 Ventro-lateral. 
3. 9 Ventro-mesial. 
4. 9 Nucleus dorsalis. 

i. 10 Axones to direct cerebellar tract. 
5.° Cells of posterior column. 
3. 4 White matter. 

i. 5 Composition and structure. 
2. 5 Fiber tracts. 

i. 6 Evidences of tracts. 
i. 7 Embryological. 
2. 7 Pathological. 
3. 5 Columns. 
i. 6 Anterior. 

i. 7 Direct pyramidal tract. 
2. 7 Anterior ground bundle. 
i. 8 Largely association fibers. 
2. 6 Posterior. 

i. 7 Funiculus gracilis. 

I. 8 Nuclei of origin and termination. 
2. 7 Funiculus cuneatus. 

i. 8 Nuclei of origin and termination. 
3. 6 Lateral. 

i. 7 Direct cerebellar tract. 

i. 8 Origin, course and termination. 
2. 7 Tract of Gowers. 

i. 8 Origin, course and termination. 
3. 7 Crossed pyramidal tract. 

i. 8 Origin, course and termination. 
4. 7 Lateral ground bundle. 

i. 8 Largely association or intersegmental. 
2 Spinal bulb (Medulla oblongata). 

I. 8 General areas anterior, posterior and lateral as in cord. 
2. 3 Components of areas differ from those of the cord. 
3. 3 Areas. 



170 A LABORATORY GUIDE IN HISTOLOGY. 

i. 4 Anterior or pyramid. 

I. 5 Direct and crossed pyramidal tracts. 
2. 5 Change in anterior ground bundle. 
2. 4 Posterior. 
i. 5 Lower half. 

i. 6 Cuneate and gracile nuclei. 
2. 5 Upper half. 

i. 6 Corpus restiforme. 
i. 7 Composition. 

i. 8 Cerebello-olivary fibers. 

i. 9 Nature of tract. 
2. 8 Direct cerebellar tract. 
3. 8 Superficial arcuate fibers. 

i. 9 Anterior from cuneate and gracile nuclei 

of the opposite side. 
2. 9 Posterior from cuneate and gracile nuclei 
of the same side. 
3. 4 Lateral area. 

i. 5 "Comparison with corresponding area of the cord. 
2. 5 Inferior olivary nucleus. 
4. 3 Motor decussation and changes produced thereby. 
5. 3 Fillet decussation and changes produced thereby. 
i. 4 Origin of fibers of the mesial fillet. 
2. 4 Course of fibers of the mesial fillet. 
3. 4 Termination of fibers of the mesial fillet. 
6. 3 Nuclei of cranial nerves. 
i. 4 Nucleus of twelfth nerve. 
2. 4 Nucleus of eleventh nerve. 
3. 4 Nucleus of tenth nerve. 
4. 4 Nucleus of ninth nerve. 
7. 3 Nucleus arcuatus. 

i. 4 Location and connexions. 
3. 2 Pons. 

I. 3 Extent and relations. 
2. 3 Parts. 
3. 3 Fibers. 

i. 4 Fibers of pyramidal tracts. 

2. 4 Transverse fibers of pons, mainly the middle pedun- 
cles of the cerebellum. 



A LABORATORY GUIDE IN HISTOLOGY. 171 

3. 4 Posterior long, bundle. 
4. 4 Mesial fillet. 

5/ Inferior cerebellar peduncles. 
6. 4 Smaller fiber tracts of pons. 
7. 4 Superior cerebellar peduncle. 
4. 3 Nuclei. 
I. 4 Pontine. 

2. 4 Mesial reception nucleus of eighth nerve. 
3. 4 Nucleus of sixth nerve. 
4. 4 Superior olivary nucleus. 
5. 4 Nucleus of seventh nerve. 
6. 4 Reception nuclei of vestibular branch of eighth 

nerve. 
7. 4 Motor nucleus of fifth nerve. 
8. 4 Reception nucleus of fifth nerve. 
9. 4 Substantia ferruginea. 
4. 2 Cerebellum. 

I. 3 General structure. 
i. 4 Gray cortex. 
2. 4 Central white core. 
2. 3 Subdivisions. 
3. 3 Histology. 
i. 4 Laminae. 

i. 5 Central core of white matter. 
i. 6 Axones of cerebellar cells. 
2. 6 Association fibers of cerebellum. 
3. 6 Axones of cells in other parts of nervous sys- 
tem. 
2. 5 Gray cortex (cortex cerebelli). 
i. 6 Internal or nuclear layer. 
i. 7 Large or small granule cells. 

I. 8 Distribution of processes of each kind of 
cell. 
2. 6 Layer of flask shaped cells (Purkinje), 
i. 7 Dendrites. 
2. 7 Axones. 
3. 7 "Basket cells." 
3.° Molecular layer. 

i. 7 Cells of molecular layer. 



i;2 A LABORATORY GUIDE IN HISTOLOGY. 

T. 8 Large and small multipolars. "Basket 
cells." 
2.' Fibers of molecular layer. 
3. 5 N iclei. 

i. 6 Nucleus dentatus most important. 

I. 7 Axones of cells largely go to form the super- 
ior cerebellar peduncle. 
2. 6 Smaller nuclei. 
I. 7 N. emboliformis. 
2. 7 N. fastigii. 
3/ N. globosus. 
4. 3 Peduncles. 

i. 4 Inferior or corpus restiforme. 

i. 5 Connexions established. 
2. 4 Middle. 

i. 5 Connexions established. 
3. 4 Superior. 

i. 5 Connexions established. 
5. 3 Blood supply. 
5. 2 Mesencephalon. 

i. 3 Location, extent, and relations. 
2. 3 Fiber tracts. 

i. 4 Superior cerebellar peduncles. 
2. 4 Mesial and lateral fillets. 
3. 4 Posterior long, bundle. 
4/ Fibers of pyramidal tracts. 
3. 3 Sylvian gray matter. 
4. 3 Nuclei. 

i. 4 Mesencephalic nucleus of fifth nerve. 
2. 4 Nucleus of fourth nerve. 
3. 4 Nucleus of third nerve. 
4. 4 Nucleus ruber. 
5. 4 Corpora quadrigemini. 
i. 5 Superior. 
i. 6 Structure. 
2. 6 Connexions. 
3. 6 Function. 
2. 5 Inferior. 



A LABORATORY GUIDE IN HISTOLOGY. 173 

I. 6 Structure. 
2. 6 Connexions. 
3. 6 Function. 
6. 4 Substantia nigra. 
6. 2 The Diencephalon. 
I. 3 Nuclei. 

i. 4 Optic thalami. 
i. 5 Location. 
2. 5 Structure. 
i. 6 Fibers. 
2. 6 Nuclei. 

i. 7 Pulvinar or posterior. 
2. 7 Anterior. 
3/ Mesial. 
4. 7 Lateral. 
2. 4 Nucleus candatus. 
i. 5 Structure. 
2. 5 Connexions. 
3. 4 Nucleus lenticularis. 

i. 5 Structure. 
4/ Hypothalamic nuclei. 
5. 4 Nucleus of post. long, bundle. 
6. 4 Mesial geniculate body. 
7. 4 Lateral geniculate body. 
8. 4 Corpora mammillaria. 
2. 3 Fiber tracts. 
i. 4 Capsules. 

i. 5 Mesial or internal. 
2. 5 Lateral or external. 
2. 4 Fibers of superior cerebellar peduncles from nucleus 
ruber. 
3. 8 Pineal body. 
7. 2 The Telencephalon. 
i. 3 Parts. 

I. 4 Hypophysis cerebri (posterior lobe). 

1. 5 Histology. 
2. 4 Hemisphere. 

1. 6 Cortex or pallium. 
i.° Histology. 



174 A LABORATORY GUIDE IN. HISTOLOGY. 



i. 7 Cell layers. Varies according to the function 
of the various parts. 
i. 8 In motor area. 

i. 9 Molecular layer. Structure. 

2. 9 Outer polymorphous layer. 

3. 9 Layer small pyramidal cells. 

4. 9 Layer large pyramidal cells. 

5. 9 Inner polymorphous cell layer. 
2. 8 Cortex of parietal lobe, frontal lobe, convex 
surface of the occipital lobe. 

i. 9 Molecular layer. 

2. 9 Outer polymorphous cell layer. 

3. 9 Layer small pyramidal cells. 

4. 9 Layer large pyramidal cells (outer). 

5. 9 Layer of granular cells. 

6. 9 Layer large pyramidal cells (inner). 

J. 9 Inner polymorphous cell layer. 
3. s Visual area cortex occipital lobe. 

i. 9 Molecular layer. 

2. 9 Outer polymorphous cell layer. 

3.° Layer of small pyramidal cells. 

4. 9 Layer of large pyramidal cells. 

5. 9 Outer stripe or pyramidal plexus (tan- 
gential fibers). 

6. 9 Granule cell layer. 

J 9 Inner stripe or polymorphous plexus 
(tangential fibers). 

8. 9 Inner polymorphous cell layer. 
4. 8 Auditory area of temporal lobe (similar to 

seven layers of parietal lobe. 
5. 8 Rhinencephalon. 

i. 9 Molecular layer. 

2. 9 Polymorphous cell layer (cells grouped). 

3. 9 Layer of pyramidal cells. 

4. 9 Inner polymorphous cell layer. 
2. 7 Fibers of cortex. 
i. 8 Commissural. 
2. 8 Association. 

I. 9 Long and short. 
3. 8 Projection. 



INDEX 



Page 

Acid-Alcohol 113 

Acid-fuchsin 109 

Active Glands 52 

Adenoid Tissue 42 

Adrenal Body 64 

Alcohols, Graded ...113 

Alimentary Tract 49 

Ammonia Alum 114 

Aorta 40 

Appendix vermiformis 55 

Areolar Tissue 23 

Bichloride of Mercury Ill 

Bladder 65 

Blood 34 

Blood, Outline of 123 

Blood, Frog 37 

Blood, Bird 37 

Blood-clot 39 

Blood Vascular System Outline.. 124 

Blood Vessels ; 40 

Blood Vessels in Optical Section. 41 

Boehmer, Hematoxylin 107 

Bone '. 27 

Bone, Developing 26, 27 

Bone Marrow, Red 39 

Bone Marrow, Outline 126 

Borax-carmine 108 

Capillaries 42 

Cartilage 24 

Cartilage, Calcification of 26 

Cardiac Muscle 34 

Cardiac Glands 50 

Carnoy's Fluid 112 

Carmine-Gelatin (Ranvier) 114 

Caustic Potash 110 

Cells, Plant 14 

Cells, Animal 16 

Cell Movements 16 

Cell, Outline of " 116 

Celloidin 114 

Celloidin — Imbedding 8 

Central Nervous System Outline.. 168 



Page 

Cerebellum 103 

Cerebrum 105 

Choroid 88 

Chromic Acid Ill 

Clearing Fluids 115 

Connective Tissues 22 

Connective Tissue, Outline of.... 120 

Connective Tissue, Areolar 23 

Connective Tissue, Embryonic. ... 24 

Congo Red 108 

Cornea 87 

Cowper's Gland 71 

Crosses of Ranvier 100 

Crystalline Lens 90 

Delafield's Hematoxylin 107 

Digestive Glands 56 

Digestive System, Outline of 136 

Ductless Glands, Outline of 162 

Ductus deferens 68 

Duodenum 53 

Ear 91 

Ehrlich's Acid Hematoxylin 108 

Ehrlich-Biondi Mixture 109 

Elastic Fibro-cartilage 25 

Elastic Tissue 23 

Embryonic Connective Tissue ... 24 

Endothelium 21 

Eosin 110 

Epididymis 6S 

Epithelium, Ciliated 19 

Epithelium, Columnar 20 

Epithelium, Squamous of Frog. . . 18 
Epithelium, Squamous Stratified.. 18 
Epithelium, Transitional Stratified 19 

Ether-alcohol 115 

Esophagus 49 

Eycleshymer, Mixtures of 115 

Eye S7 

Eyelid 90 

Eye, Outline of 152 

Fallopian Tube 74 

Farrant's Gum-glycerine 114 



INDEX— Continued. 



Page 

Fat Cells 24 

Female Reproductive Organs 71 

Female Reproductive Organs, Out- 
line of 149 

Fertilization, Outline of 118 

Fetal Kidney 64 

Fetal Scalp 79 

Fibro-cartilage 25 

Fibrous Tissue 22 

Fish, Modified Golgi Method 94 

Fixing Fluids Ill 

Flemming's Fluid 112 

Formalin 112 

Formalin-Muller's Fluid 112 

Formulae for Reagents 107 

Fundus Glands 51 

Fungiform Papillae 47 

Gall Bladder 60 

Ganglia 98 

Ganglia, Outline of 167 

General Suggestions 5 

Glands, Outline of 133 

Glycogen 25 

Graded Alcohols 113 

Hair 79 

Harris, Stain of 109, 25 

Hatai's Fluid 113 

Heidenhain's Iron-Hematoxylin. . .109 

Hemin Crystals 37 

Hemoglobin Crystals 38 

Hemolymph Xode . . . 45 

Hyaline Cartilage 24 

Hydrochloric Acid 110 

Hypophysis cerebri 106 

Ileum 53 

Imbedding Tissues 8, 12 

Karyokinesis 14 

Kidney 61 

Kidney, Outline of 144 

Larynx 81 

Liver 58 

Liver, Outline of 143 

Lugol's Solution 114 

Lung 82 

Lung, Outline of 140 

Lymphatic Tissues, Outline of... 127 



Page 

Lymphoid Tissue 42 

Lymph Xode or Gland 44 

Lymph Xode or Gland, Cells of . . . 45 

Macerating Fluids 110 

Male Genital Organs, Outline of. 147 

Male Reproductive Organs : 67 

Mammary Gland 75 

Mammary Gland, Outline of .... 161 

Marrow, Red 39 

Mayer's Albumin Fixative 113 

Medulla oblongata 102 

Mesencephalon 103 

Mesothelium 21 

Mitosis 14 

Muller's Fluid Ill 

Muscle 31 

Muscle, Cardiac 34 

Muscle, X T on-striated 34 

Xails 80 

Nerve Cells 93 

Nerve Endings 99 

Xerve Fibers 95 

Nerve Histology 93 

Xerve Tissues, Outline of 164 

Xitric Acid Ill 

CBsophagus 49 

Oil of Bergamot 115 

Oil of Cloves 115 

Oil of Origanum 115 

Olfactory Mucosa 92 

Orcein 109 

Organ of Hearing, Outline of . . . 154 

Organ of Smell, Outline of 158 

Outlines of Histology 116 

Ovary 71 

Pacinian Corpuscles 100 

Palpebra 90 

Pancreas 57 

Pancreas, Outlines of 142 

Paraffin Imbedding . . 12 

Parotid Gland 56 

Penis 69 

Phenol 115 

Phenol-xylol 115 

Pituitary Body 106 

Pons 103 



INDEX— Continued. 



Page 

Prostate 70 

Pyloric Glands 51 

Ranvier, Crosses of 100 

Ranvier's One-third Alcohol ....110 
Ranvier's Lemon-juice Method... 99 

Reagents 107 

Respiratory System, Outline of. . .139 

Resting Glands 52 

Retina 89 

Saf ranin 108 

Salivary Glands, Outline of 141 

Scalp 77 

Sclera 88 

Skin 76 

Skin, Outline of : ....... 159 

Solitary Nodule 42 

Spinal Bulb 102 

Spinal Cord 100 

Spleen 45 

Staining 10 

Stains 107 

Stomach 50 

Sublingual Gland 57 

Submaxillary Gland 57 

Suprarenal Body 64 



Page 

Taste Buds 48 

Teichmann's Crystals 37 

Teeth 28 

Teeth, Development of 30 

Teeth, Outline of 131 

Testis 67 

Thionin 109 

Thymus Gland 43 

Thyroid - 86 

Tissue Imbedding 8 

Tissues, Outline of 119 

Tissue Preparation 7 

Tongue '. 47 

Tongue, Outline of 135 

Tonsil 43 

Ureter 65 

Urogenital System, Outline of . . . .144 

Uterus 74 

Vagina 75 

Van Gieson's Stain 109 

Vas deferens 68 

Veins 41 

Vermiform Appendix 55 

Weigert's Hematoxylin 108 

Xylol 115 



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